client.query("ROLLBACK"); } } finally { client.release(); } execute(); 上面的代码正在工作,尽管我想在事务中放置两个if-else条件块,如果满足条件,它将触发2个查询,如果是true还是false,它将继续执行if (someCondition == 1)条件块。 下面是两个if-else条件: if (conditionA == true) { await pool...
在vb.net控制台应用程序(X64)上使用odbc连接器(X64)连接到postgresql数据库时出现问题,错误为 Dim ConnectionString = "Driver={PostgreSQL UNICODE};Server=myPGSrv;Port=5432;Database=dbDefault;Uid=postgres;Pwd=pw;" 'Dim ConnectionString = "ODBC;dsn=PostgreSQL35W" conn = New OdbcConnection(ConnectionSt...
最近一直在寻找，如何不通过 select count(*) from table where 字段 = ‘值’ 类似这样的语句，大约...
在PostgreSQL中,这些规则可以通过函数和触发器来实现。PostgreSQL函数也称为PostgreSQL存储过程。首先我们简要介绍函数这个概念。PostgreSQL存储过程具有以下优点减少应用与数据库服务器通信开销,提升网络性能。在某些大型业务系统中,大多 POSTGRESQL存储过程详解 数据库 python php 存储过程 PostgreSQL中存储过程 PLSQL包,函数,...
You can formulate conditional expressions in PostgreSQL using WHEN-THEN case which is very similar to if-else blocks. In this tutorial, you will learn how to do this. Before you start writing condition queries, it is important that you set up a local PostgreSQL database. You will do this ...
SQL92 的 UNION/INTERSECT/EXCEPT 语法允许一个附加的 CORRESPONDING BY 选项: table_query UNION [ALL] [CORRESPONDING [BY (column [,...])]] table_query 1. 2. 3. 4. CORRESPONDING BY 目前还不被 PostgreSQL支持. SQL语句(inner join,left out join,right out join三者的不同用法) ...
API PostgreSQL C# PostgreSQL PHP PostgreSQL Python PostgreSQL JDBC Back to Docs PL/pgSQL IF Statement Summary: in this tutorial, you will learn how to use the PL/pgSQL if statements to execute a command based on a specific condition. Introduction to PL/pgSQL IF Statement The if statement al...
I'm trying to run an insert query where it will insert to a table if the data has all parameters; else, if there are missing parameters, insert nulls as values. An example would be some records will not have last_delivery nor volume_rate parameters. So how can I ...
1 postgresql, odd OFFSET/LIMIT behavior ( records order ) 3 slow order by "field" and limit 7 Flask-SqlAlchemy query with order_by and pagination is very slow 8 PostgreSQL: Terribly slow ORDER BY with primary key as the ordering key 8 Slow Postgres query using LIMIT ...
Additionally, PostgreSQL doesn’t support an IIF() or IF() function. 3.2. Example Query Let’s repeat the example from the previous section, but this time, we’ll use the IIF() function instead of the CASE expression. Let’s evaluate the grade column in SQL using IIF(): SELECT student...