Hql Count Distinct

The criteria query API lets you build nested, structured query expressions in Java, providing a compile. Hibernate HQL Count Distinct not working? I want to count the distinct users that rated on an item. A Standard Score is a statistical measurement of a score’s relationship to the baseline of a group. In this tip, I show how to do this using a query as well as graphically in SQL Server. The original query: SELECT count( * ) +1 FROM ( SELECT. Since MySQL doesn’t have window functions, we’ll do something similar using group_concat. If your data lends itself to this method, you could use something like the hash () or md5 () function. The SQL SELECT DISTINCT syntax The general syntax is: SELECT DISTINCT column-name FROM table-name Can be used with COUNT and other aggregates SELECT COUNT (DISTINCT column-name) FROM table-name. mid) as temp. weight), sum(cat. He has authored 12 SQL Server database books, 24 Pluralsight courses and has written over 4900 articles on the database technology on his blog at a https://blog. SELECT COUNT (*) FROM (SELECT DISTINCT column1, column2 FROM table1) to get the number of results for a distinct query. -- NULL is not included as a distinct value in the count. HQL的几个小问题 ; 5. The following are top voted examples for showing how to use org. Additional Resources Learn to become fluent in Apache Hive with the Hive Language Manual:. Esse erro dá somente com o hibernate ou ocorre quando vc executa a query sql no banco mesmo. SQL CEIL() function with distinct Sample table : agents To get the unique ceiling or nearest rounded up value of the column 'commission' after multiplying by 75 from the 'agents' table, the following SQL statement can be used :. The below post describes how you can use a Dynamic Query Library provided by the LINQ team to dynamically construct LINQ queries. Sometimes we want to change the name of a column. Introduction to HQL. Aggregating Distinct Values with DISTINCT. In this article we will see how the WHERE clause can be used to select specific rows from the table that match certain specified criteria or conditions. For more information, see Requirements for updatable cursors and updatable ResultSets. city = cities. Hi, There is a SELECT statement which returns columns (around no of coloums are 25). SQL Service: SQL Service is the entry point for working along structured data in Spark. We initially called List on the criteria at this point, and received the same data back from the HQL version â€" and ArrayList of object[]. Hibernate provides alternate ways of manipulating objects and in turn data available in RDBMS tables. weight), max(cat. The aggregate functions array_agg , string_agg , and xmlagg , as well as similar user-defined aggregate functions, produce meaningfully different result values depending on the order of the input values. These old forums are deprecated now and set to read-only. You may wish to use executeQuery in this case so you have more flexibility in specifying what gets returned. ROW_NUMBER is an analytic function. Edit: I misread the post. I do not need this feature in most cases. Hibernate Query Language (HQL) supports various aggregate functions - min(), max(), sum(), avg(), and count() in the SELECT statement. RANGE use a count of distinct values. 0 (HIVE-9194). Supposing Acts in following HQL example is generic,. The second part of my Spring Data JPA tutorial described how you can create a simple CRUD application with Spring Data JPA. JPQL, HQL or Criteria API), you can use any SQL function without having to register it as long as the function is passed directly to the WHERE clause of the underlying SQL statement. SQL ORDER BY Descending and ascending Command The results we get from a table we may have to display in an order. 关键字 distinct 与 all 也可以使用,它们具有与 SQL 相同的语义。 select distinct cat. You can use the count() function in a select statement with distinct on multiple columns to count the distinct rows. HQL is fully object-oriented, understanding notions like inheritance, polymorphism and association. persistence. HqlQuery is a little. This has the side effect of leaving the file open, but can be useful in short-lived programs, like shell scripts. id))onum,count(distinct(i. g" -> "HqlBaseParser. Count distinct value in HQL. HQL不支持select count(*) from (select distinct x, y from xx); 即:HQL不支持from语句中的子查询。 PS: hql不能在distinct,group by结果集上使用count的问题 !. Hi All, HQL does not support sub query after from. select count(*) from (select distinct trainOrder. I have the following HQL query that is attempting to return 2 object instances as well as an aggregate count based upon a 3rd object instance. 1, 1111SP20, 1111SP30 etc. Use this handy cheat sheet (based on this original MySQL cheat sheet) to get going with Hive and Hadoop. *Raihan Jamal*. HQL(Hibernate Query Language):是面向对象的查询语句,它的语法和 SQL 语句 有些相像,在运行时才得以解析. HQL is fully object-oriented, understanding notions like inheritance, polymorphism and association. 1 SELECT count(*) FROM Author a. 我看过一篇文章上说。。不管什么数据库 一定不要用 select * 或 count(*)、还有就是你说的 distinct 这些语句都是最浪费效率的。. user)) from Rating as r where r. count wordCounts: org. Hive Join-HiveQL Select Joins Query, types of joins in hive, Inner join, Left & Right Outer Join, Full Outer Joins in Hive with examples, hive join clause. Aggregate functions, when used in HQL queries, return an aggregate value (such as sum, average, and count) calculated from property values of all objects satisfying other query criteria. Hibernate HQL examples The Hibernate Query Language (HQL) is similar to SQL. PERCENTILE_CONT (Transact-SQL) 10/20/2015; 2 minutes to read +1; In this article. Now customize the name of a clipboard to store your clips. Count()–>Count() function is used to count the records in the table. hql count 与取到的值 取不到值 提取值到表 value取不到值 count count hql 值的获取 count(*) count count count DropDownList的取值 取值 HQl hql hql hql hql hql 0 BEGIN SET count = count - 1; END Compatibility: Oracle, Teradata, IBM DB2, Microsoft SQL Server, MySQL, PostgreSQL and Netezza. UPDATE: How do I find the standard deviation of columnC? Need this asap. In this section, we will illustrate how summary information can be obtained from groups of rows in a table. -- NULL is not included as a distinct value in the count. It can be done in two ways. The "*" is a Hibernate HQL extension to JPA QL. HQL queries may even return the results of aggregate functions on properties: select avg(cat. How do I accomplish this please in T-SQL. Union All does not eliminate duplicate rows and returns all the rows from all the tables. Professional Open Source™ HQL© JBoss, Inc. In other cases you might have values in multiple rows and want them to be a single value separated by comma or some other character. Upload by Cafeitvn. Tag: java,sql,hibernate,hql. txt) This example Hibernate source code file (changelog. Problem that I cant count objects in query. openSession(); String countHql = "Select count (distinct salary. Expression JPA interface Type for query expressions. Aliases–> Alias is nothing but the obfuscation technique to protect the real names of database fields. Az SQL-el szemben azonban teljesen objektumorientált, így olyan lekérdezéseket írhatunk benne, melyekben a táblák és oszlopok helyett osztályneveket és adattagokat használhatunk. It thus gets tested and updated with each Spark release. Below is the general format of the INTERSECT operator. * * @return True if the database supports counting distinct tuples; false otherwise. Instead of getting the Address object, just get the Address id. store_type));. 5 【超軽量ジュラルミンナット】kyo-ei/kics. SUM: SUM(DISTINCT column) to calculate the sum of distinct values. If none of these options are given, the default is ALL (all matching rows are returned). BasicQuery query1 = new BasicQuery("{ age. As a result, the return type from the following projections in org. These can be found in the src-test folder in the Openbravo ERP project. startsWith("t")). Just like any other SQL keyword, usage of these functions is case-insensitive. Hibernate Interceptor / Listeners para HQL; java - Hibernate HQL Query: ¿Cómo configurar una colección como un parámetro con nombre de una consulta? java - Inner join usando HQL; java - Hibernate HQL Count Distinct no funciona? java - HQL Hibernate INNER JOIN; java - Hibernate parece crear una consulta SQL incorrecta desde una consulta HQL. In this accelerated training, you'll learn how to use formulas to manipulate text, work with dates and times, lookup values with VLOOKUP and INDEX & MATCH, count and sum with criteria, dynamically rank values, and create dynamic ranges. Esta secuencia de comandos SQL funciona bien en mi servidor SQL server: SELECT COUNT (DISTINCT linkedin_id) as test, school_name FROM (SELECT * FROM alum_education UNION SELECT * FROM alum_connection_educations) AS UNIONS where school_name = 'some. Arm Treasure Data provides a SQL syntax query language interface called the Hive query language. HQL中 distinct 和 count [问题点数:100分,结帖人machao299]. create managed table. distinct一点收获; 10. Aliases-> Alias is nothing but the obfuscation technique to protect the real names of database fields. APPLIES TO: SQL Server Azure SQL Database Azure SQL Data Warehouse Parallel Data Warehouse. This is a case where using HQL with GORM makes life simpler. Dans le langage SQL, la fonction d’agrégation SUM() permet de calculer la somme totale d’une colonne contenant des valeurs numériques. As a result, the return type from the following projections in org. There isn't any way to separate the counts as separate columns, though, is there?. The main difference between is HQL uses class name instead of table name, and property names instead of column name. However, as the table is scanned, locks are being held. COUNT(*) returns the number of rows in a specified table, and it preserves duplicate rows. QuerySyntaxException: expecting CLOSE, found ',' near line 3, column 67 Tu utilises deux arguments pour ta fonction count(). The SQL UNION ALL operator is used to combine the result sets of 2 or more SELECT statements. Helps DBA to find out quickly which database takes a lot of space and which file could be shrunk. numOfGoodsOrder) from GoodsDealer gd");. size() but this workaround has overhaed in performances) Thanks. If COUNT is used, and there are no values to which COUNT can be applied, the result of the aggregate function is 0. Alert: Welcome to the Unified Cloudera Community. What is the difference between COUNT(DISTINCT) vs COUNT(ALL)? I found this question from the student very interesting. SQL allows us to concatenate strings but the syntax varies according to which database system you are using. The term MapReduce represents two separate and distinct tasks Hadoop programs perform-Map Job and Reduce Job. If this is your first visit, be sure to check out the FAQ by clicking the link above. hql不能在distinct,group by结果集上使用count的问题,报语法错误 09-01 阅读数 3122 hql有如下两个限制:HQL(SQL)不支持selectcount(distinctx,y)fromxx;HQL不支持selectcount(*)from(selectdistinctx,yfromx. DISTINCT: Allows you to request information from only one row of identical rows. Complete journey starting from JDBC to JPA to Spring Data JPA using an example with Spring Boot Data Jpa starter project. Use a subquery when you need no columns from the tables referenced in the subquery. HQL is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with. The CHAR and VARCHAR types are declared with a length that indicates the maximum number of characters you want to store. You can use aggregate functions like count, sum, avg, min, max etc. JPQL, HQL or Criteria API), you can use any SQL function without having to register it as long as the function is passed directly to the WHERE clause of the underlying SQL statement. To do that, you must drop and recreate the function. As always, the above is much easier to understand by example. It counts each row separately. magId后不希望出现',' 请问这用hql该怎么写,别说用sql处理,谢谢!. Edit: I misread the post. A JOIN locates related column values in the two tables. SELECT CASE WHEN ispostpaid=0 AND subscriber_status='active' THEN COUNT(DISTINCT S. 如题,用Hibernate做分页,当HQL查询语句中包含distinct时,就不能正确count出结果集总行数,如:String hqlQuery = "select distinct u. HQL queries can return domain class instances, or `Array`s of specified data when the query selects individual fields or calculated values. Search for: Home. Spark SQL is developed as part of Apache Spark. As a result, the return type from the following projections in org. The general syntax of an aggregate function is: agg_func([ALL | DISTINCT] expr) agg_func is MIN, MAX, SUM, AVG, or COUNT. Excel Formula Training. FROMDATE <= ?) Using both HQL and Criteria , then HQL will run much faster. ROW_NUMBER is an analytic function. I have this HQL (doesn't look nice, I know): Code: select count(*) from Pripomienka as p where 1=1 AND p. hql执行update行为时可能遇到的一个问题。 8. Constraints can be placed on a table to limit the type of data that can go into a table. Queries written in HQL are database independent. weight), sum(cat. count(1) ct, row_number() over (partition by dt order by ct desc) row_num from gameplays group by 1, 2) twhere row_num = 1. Hibernate Count Query In this section we will show you, how to use the Count Query. These enhancements are often times referred to as the windowing functions. HQL queries are translated by Hibernate into conventional SQL queries which in turns perform action on database. The syntax for TOP is as follows:. Union All does not eliminate duplicate rows and returns all the rows from all the tables. A blog for beginners to advance their skills in programming. userid) FROM pv_users GROUP BY pv_users. 在hql中使用left jion 遇到的问题 org. However, one can still count distinct items in a window by using another method. One of my favorite T-SQL hacks ever is one that can flatten out data by taking a value from multiple rows and concatenating the values into a single string. Converting Z Score to SQL/HQL The Z Score A. Introduction to MySQL ORDER BY clause. SUM: SUM(DISTINCT column) to calculate the sum of distinct values. A Standard Score is a statistical measurement of a score’s relationship to the baseline of a group. Az SQL-el szemben azonban teljesen objektumorientált, így olyan lekérdezéseket írhatunk benne, melyekben a táblák és oszlopok helyett osztályneveket és adattagokat használhatunk. Calculates a percentile based on a continuous distribution of the column value in SQL Server. で、この話、Google で日本語で「Hibernate Criteria count」とかしても「できないっぽい」「できません」「HQL使っとけ」てな話ばかりで(3. You can vote up the examples you like. In this post, we will discuss about Bucketing in Hive with example use cases and perform basic sampling on the bucketed tables. name), count (cat) from Cat cat 1. userid, trainOrder. HQL queries are translated by Hibernate into conventional SQL queries which in turns perform action on database. Spark SQL, DataFrames and Datasets Guide. DISTINCT Specifies that each unique value is considered. DISTINCT operates on a single column. The only way I found is to do a select count(*) from (select distinct , but JPA specifications doesn't allow it. SELECT DISTINCT eliminates duplicate records from the results. If none of these options are given, the default is ALL (all matching rows are returned). SQL: Counting Groups of Rows Sharing Common Column Values. cn):综合教育门户网站】. age) FROM Author a. Summary: in this tutorial, you will learn how to use the MySQL LIKE operator to query data based on a specified pattern. 0 the following HQL query select count(distinct hit. COUNT(*) does not require an expression parameter because by definition, it does not use information about any particular column. SQL > Advanced SQL > Top. (our work around is to return the list. The main difference between is HQL uses class name instead of table name, and property names instead of column name. In SQL, of which HQL is a dialect, querying data is performed by a SELECT statement. Java JDBC FAQ: Can you share an example of a SQL SELECT query using the standard JDBC syntax? In my JDBC connection article I showed how to connect your Java applications to standard SQL databases like MySQL, SQL Server, Oracle, SQLite, and others using JDBC. Hibernate HQL examples The Hibernate Query Language (HQL) is similar to SQL. est-il possible de créer une requête distincte dans HQL. This article explains the functionality and uses of the LEFT, RIGHT, SUBSTRING and CHARINDEX functions in SQL. Hibernate Query Language (HQL) is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with persistent objects and their properties. These old forums are deprecated now and set to read-only. Hibernate Criteria API is a more object oriented and elegant alternative to Hibernate Query Language (HQL). For example, they show the following code to use both distinct and count. 5 This is the hbm file:. 在OLAP多维分析中,Count Distinct(去重计数)是一种非常常用的指标度量,比如一段时间内的UV、活跃用户数等等; 从1. SQL COUNT Examples. createSQLQuery(que ry). If the number n is greater than the number of rows in the table, the sample will consist of the number of rows in the table. The solution I provided above works for OR statements not AND. age) FROM Author a. Just like any other SQL keyword, usage of these functions is case-insensitive. SQL DISTINCT with aggregate functions. These old forums are deprecated now and set to read-only. 一个如下的查询语句: from Cat as cat 不仅返回 Cat 类的实例,也同时返回子类 DomesticCat 的实例。. autor LIKE :externyAutor_ and exists ( from Komentar k. Upload by Cafeitvn. Learn to use Union, Intersect, and Except Clauses. size() but this workaround has overhaed in performances) Thanks. Hibernate Query Language (HQL) is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with persistent objects and their properties. Distinct keyword:–>The Distinct keyword is very useful keyword which will eliminate duplicates and fetches the Result. Map job scales takes data sets as input and processes them to produce key value pairs. The syntax of the Java Persistence Query Language (JPQL) is very similar to the syntax of SQL. How To Dedupe A Table Based On A Unique Key What's the best way to dedupe a table on the unique key? So far I can find out the number of duplicates by using the SQL below however how do I delete the duplicates leaving only 1 record for each custno (as you see below the count varies)?. Soit en utilisant le mot-clé" distinct " ou une autre méthod ct est un travail de clé valide pour HQL, mais je suis à la recherche de L'équivalent HQL du mot-clé SQL "distinct". The HAVING clause with SQL COUNT() function can be used to set a condition with the select statement. We can use any of the available variations of the count() function – count(*), count(…), count(distinct …), or count(all …). You can use CASE WHEN THEN clause also. A combination of same values (on a column) will be treated as an individual group. SAMPLE n - Will results a sample of n rows. If you have questions about the system, ask on the Spark mailing lists. Converting Z Score to SQL/HQL The Z Score A. How to work with Projection in Hibernate Criteria Query (HCQ) In this article we will discuss about making use of projections in Hibernate Criteria Query (HCQ). [HQL]count and distinct on multiple columns forum. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages, [12] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and. If SELECT DISTINCT is specified or if the SELECT statement contains a GROUP BY clause, the ORDER BY columns must be in the SELECT list. The following table presents the various SQL statements and the corresponding MongoDB statements. -- Returns the unique values from one column. item =: item group by r. HQL allows representing SQL queries in object-oriented terms—by using objects and properties of objects. Page Tools. age) FROM Author a. Hive supports subqueries only in the FROM clause (through Hive 0. 21 * 51 Franklin Street, Fifth Floor 22 * Boston, MA 02110-1301 USA 23 * 24 */ 25 package org. The Java Persistence Query Language (JPQL) is discussed in the next two sections. Introduction to MySQL LIKE operator. are not case sensitive but properties like table and column names are case sensitive in HQL. I want to know how many employeed or unemployeed applicants was in last month as so on. hql语句: select count(*) from ( select stu. Helps DBA to find out quickly which database takes a lot of space and which file could be shrunk. The UNION, INTERSECT, and EXCEPT clauses are used to combine or exclude like rows from two or more tables. store_type));. Hibernate Query Language (HQL) is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with persistent objects and their properties. He has authored 12 SQL Server database books, 24 Pluralsight courses and has written over 4900 articles on the database technology on his blog at a https://blog. Current implementation has the limitation that no ORDER BY or window specification can be supported in the partitioning clause for performance reason. HQL supports the use of ANSI SQL row value constructor syntax, sometimes referred to AS tuple syntax, even though the underlying database may not support that notion. The following table presents the various SQL statements and the corresponding MongoDB statements. Along with 16+ years of hands on experience he holds a Masters of Science degree and a number of database certifications. In SQL, of which HQL is a dialect, querying data is performed by a SELECT statement. xtype in ('U') and o. Aggregate functions HQL queries can even return the results of aggregate functions on properties: select avg(cat. create managed table. if you are using information_schema. 导读 HQL(Hibernate Query Language) 是面向对象的查询语言, 它和 SQL 查询语言有些相似. The below SQL query make use of correlated subquery wherein in order to find the 3rd highest salary the inner query will return the count of till we find that there are two rows that salary greater than other distinct salaries. The syntax for TOP is as follows:. Dimotiv ディモーティヴ アジャスタブルショートレバー ブレーキ/クラッチセット タイプ3 エクステンションカラー:レッド ボディーカラー:ダークグリーン(アジャスターカラー:シルバー) ZX-10R,lp-z2000 compatible サンヨー Projector ランプ with ハウジング, 150 デイズ 「汎用品」(海外取寄せ品. Alert: Welcome to the Unified Cloudera Community. However, when I check total count of a report query, I have to write a hql like:. The GROUP BY with HAVING clause retrieves the result for a specific group of a column, which matches the condition specified in the HAVING clause. Many people ever asked me about the comparison of performance among Tabular, Spark and Hive. Learn to use Union, Intersect, and Except Clauses. Table: Employees. The syntax for DECODE is:. distinct = alias; return this; } /** * utility method to handle order by clauses. COUNT(*) does not require an expression parameter because by definition, it does not use information about any particular column. 이 쿼리를 수행하는 다른 방법은 User 와 join. Occasionally COUNT(*) would have a higher CPU time and sometimes COUNT(1) would have a higher CPU time. Windowing in Hive is introduced from Hive 0. ? I have attached a screen shot of both the files from linux war and windows war. HQL queries are translated by Hibernate into conventional SQL queries, which in turns perform an action on a database. HQL的几个小问题. Hibernate Interceptor / Listeners para HQL; java - Hibernate HQL Query: ¿Cómo configurar una colección como un parámetro con nombre de una consulta? java - Inner join usando HQL; java - Hibernate HQL Count Distinct no funciona? java - HQL Hibernate INNER JOIN; java - Hibernate parece crear una consulta SQL incorrecta desde una consulta HQL. Queries written in HQL are database independent. In this section we will show you, how to use the Count Query. x/nhibernate/src/NHibernate. QuerySyntaxException: unexpected token: ( near line 1, column 22 [ select count(*) from (. Hibernate provides three different ways to retrieve data from database. Java JDBC FAQ: Can you share an example of a SQL SELECT query using the standard JDBC syntax? In my JDBC connection article I showed how to connect your Java applications to standard SQL databases like MySQL, SQL Server, Oracle, SQLite, and others using JDBC. Note, Hive supports SELECT DISTINCT * starting in release 1. QuerySyntaxException: unexpected token: distinct. NULL value will not be counted. hibernate hql语句查询报错org. Choptank Sweet 40/60 Count, Diver Picked, Hand Shucked. XXXXX xxxx = (YYYYY)getSession(). The CHAR and VARCHAR types are declared with a length that indicates the maximum number of characters you want to store. gidgroupbym. I want to know how many employeed or unemployeed applicants was in last month as so on. What you want is COUNT(DISTINCT ): evaluates expression for each row in a group and returns the number of unique, non-null values. Table: Employees. userType 现在我需要统计出,上面这条语句,一共有多少结果。. HQL的几个小问题 ; 5. It looks like SQL's SELECT Query and case-insensitive. 在hql中使用left jion 遇到的问题 org. GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. HQL query problem after upgrade to HSQLDB 2. HibernateCallback. Since I explained what a bucket is in my previous tip Understanding SQL Server Memory-Optimized Tables Hash Indexes, I won't go into further details on this matter. userid, trainOrder. The OBBaseTest class. Hibernate; 28 import org. First, the structure of a JPQL query (and a criteria query) is explained by describing the main clauses of JPQL queries (SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY): JPA Query Structure (JPQL / Criteria). Hadoop Hive analytic functions Latest Hive version includes many useful functions that can perform day to day […]. In other cases you might have values in multiple rows and want them to be a single value separated by comma or some other character. This tutorial has already taught us how we can create static database queries with Spring Data JPA. The subquery has to be given a name because every table in a FROM clause must have a name. Both count and distinct are aggregation functions, and you can't aggregate an aggregated result. This article compares efficiency of these methods in SQL Server. The syntax for DECODE is:. For Example: Write the query as. if you are using information_schema. I have the following HQL query that is attempting to return 2 object instances as well as an aggregate count based upon a 3rd object instance. In those examples I showed how to. Previous Next In this section we will show you, how to use the Count Query. To do this in SQL, we specify that we want to change the structure of the table using the ALTER TABLE command, followed by a command that tells the relational database that we want to rename the column. DISTINCT will eliminate those rows where all the selected fields are identical. Besides eliminating duplicates, you can use the DISTINCT operator in conjunction with an aggregate function such as: COUNT: COUNT(DISTINCT column) to count distinct values in a result set. Prerequisites. RANK(): This one generates a new row number for every distinct row, leaving gaps between groups of duplicates within a partition. max() function returns maximum value of specified value in the table. The SQL SELECT LIMIT statement is used to retrieve records from one or more tables in a database and limit the number of records returned based on a limit value. Here, we are generally referring to multi-valued comparisons, typically associated with components. In other cases you might have values in multiple rows and want them to be a single value separated by comma or some other character. It is used to combine records from two or more t. Project Structure. The number of rows to lead can optionally be specified. The subquery has to be given a name because every table in a FROM clause must have a name. Hibernate_QL; 7. 1 SELECT count(*) FROM Author a. For example, findTitleDistinctBy or findDistinctTitleBy means that we want to select all unique titles that are found from the database. The SQL SELECT LIMIT statement is used to retrieve records from one or more tables in a database and limit the number of records returned based on a limit value. DISTINCT: Allows you to request information from only one row of identical rows. HQL queries are translated by Hibernate into conventional SQL queries, which in turns perform action on database. This problem was the bane of my existence when I first started using Hibernate because I had no idea where the problem was coming from. Hibernate Query Language (HQL) is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with persistent objects and their properties. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages, [12] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and. Well designed tables and queries can greatly improve your query speed and reduce processing cost. HQL queries can return domain class instances, or `Array`s of specified data when the query selects individual fields or calculated values. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: