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...
MySQL SUM IF – IF function with the SUM function Sample table: purchase The following SQL statement calculates and displays the total number of books purchased, categorized by whether they are published in English or in a language other than English. Explain how this is achieved using the provi...
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 (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 ...
Error: Can't update table 'table2' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. 1. 2. 这个错误的意思就是,在执行修改的时候触发一个触发器,而触发器中会执行另外一个UPDATE语句,会接着触发另一个触发器… 从而形成循环触发,因此执行失...
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 ...
function execute_all_sql_script() { for sqlfile in `ls $2` #$2 为执行脚本时后面跟的第2个参数 do if [ -d $2'/'${sqlfile} ]; then #如果是个子文件夹 则进去 递归 execute_all_sql_script $2'/'${sqlfile} else if [ "${sqlfile##*.}" = "sql" ]; then ...
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...
The COALESCE function returns the fist not NULL value from the list of values. If all the values in the list are NULL, then it returns NULL. Example: COALESCE(NULL,NULL,5,NULL,4) returns 5 CASE Statement The syntax for the case statement is: CASE [ expression ] ...