SQL 条件语句 (IF, CASE WHEN, IFNULL) 1、IF 1.1 表达式: IF( expr1 , expr2 , expr3 ) expr1条件,条件为true,则值是expr2 ,false,值就是expr3 示例; SELECT o.id,u.account,catagory
https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/113981563 除了标准 SQL 语句之外,PostgreSQL 还支持使用各种过程语言(例如 PL/pgSQL、C、PL/Tcl、PL/Python、PL/Perl、PL/Java 等 ) 创建复杂的过程和函数,称为存储过程(Stored Procedure)和自定义函数(User-Defined Function)。 存储过程支持许多过程...
CREATE FUNCTION (SQL) CREATE FUNCTION (外部) CREATE LOCATION CREATE MATERIALIZED VIEW CREATE RECIPIENT CREATE SCHEMA CREATE SERVER CREATE SHARE CREATE STREAMING TABLE CREATE TABLE 數據表屬性和數據表選項 CREATE TABLE 使用 Hive 格式 CREATE TABLE CONSTRAINT CREATE TABLE USING CREATE TABLE LIKE CREATE V...
CREATEFUNCTIONgetCustomerPaymentFunc (@customerCodebigint)RETURNSbigintASBEGINDECLARE@resultbigintSET@result=(SELECTISNULL(SUM(price),0)FROMPaymentLogWHEREcustomerCode=@customerCode)RETURN@resultEND If thecustomerCodedoesn't exist in thePaymentLogtable theSUM()function will returnNULLand you can use ei...
IF() function Introduction to MySQL IF() Function: The IF() function in MySQL is a powerful tool that allows you to implement conditional logic directly within your SQL queries. It takes three parameters: a condition to evaluate, a value to return if the condition is true, ...
if sql语句_SQL IF语句介绍和概述 大家好,又见面了,我是你们的朋友全栈君。 if sql语句 This article explores the useful function SQL IF statement inSQL Server. 本文探讨了SQL Server中有用的函数SQL IF语句。 介绍(Introduction) In real life, we make decisions based on the conditions. For example,...
CREATE FUNCTION 函数名称([参数 数据类型]) RETURNS 返回值类型 BEGIN 执行的sql语句; RETURN 结果; END$ DELIMITER ; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 调用存储函数 -- 标准语法 SELECT 函数名称(实际参数); 1. 2. 删除存储函数 ...
MySQLIF()Function ❮Previous❮ MySQL FunctionsNext❯ ExampleGet your own SQL Server Return "YES" if the condition is TRUE, or "NO" if the condition is FALSE: SELECTIF(500<1000,"YES","NO"); Try it Yourself » Definition and Usage ...
The FORMAT function can't be executed if it's wrapped inside the common language runtime (CLR) in Microsoft SQL Server 2012 Service Pack 3 (SP3), SQL Server 2014 SP2, or SQL Server 2016. This issue occurs when you set the PERMISSION...
例如,如果你遇到了一个错误,提示Invalid use of group function,这通常是因为你在SELECT语句中错误地使用了聚合函数(如COUNT、SUM等)与IF函数结合。 解决这个问题的一种方法是使用CASE语句代替IF函数,因为CASE语句在处理聚合函数时更加灵活。 代码语言:txt 复制 SELECT employee_id, salary, CASE WHEN salary > 5000...