About sales:sales@w3schools.com About errors:help@w3schools.com × SQLANDOperator ❮ PreviousNext ❯ The SQL AND Operator TheWHEREclause can contain one or manyANDoperators. TheANDoperator is used to filter records based on more than one condition, like if you want to return ...
SQL Server has many built-in functions.This reference contains string, numeric, date, conversion, and some advanced functions in SQL Server.SQL Server String FunctionsFunctionDescription ASCII Returns the ASCII value for the specific character CHAR Returns the character based on the ASCII code ...
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« W3Schools Home Next Chapter » SQL SQL is a standard language for accessing databases. Our SQL tutorial will teach you how to use SQL to access and manipulate data in: MySQL, SQL Server, Access, Oracle, Sybase, DB2, and other database systems....
SQL Aggregate FunctionsAn aggregate function is a function that performs a calculation on a set of values, and returns a single value.Aggregate functions are often used with the GROUP BY clause of the SELECT statement. The GROUP BY clause splits the result-set into groups of values and the ...
1.2 SQL的主要功能 (Main Functions of SQL) SQL的主要功能包括: 数据查询(SELECT) 数据插入(INSERT) 数据更新(UPDATE) 数据删除(DELETE) 了解这些基本操作将帮助你在后续的学习中更快上手。 2. 学习SQL的基础语法 (Learning the Basic Syntax of SQL) ...
SQL Functions ISNULL(val, replacementVal) NULLIF(val1, val2) ARRAY(val1, val2, ...) ARRAY_VAL(arrayRef, arrayIndex1, arrayIndex2, ...) RAND() GROUP BY HAVING FlexScript Expressions: you can use any FlexScript expression within an SQL expression. In some cases, however, you may nee...
https://docs.microsoft.com/en-us/sql/t-sql/functions/functions?view=sql-server-ver15 Related Keywords: sql create function, sql function example, sql function syntax, oracle sql functions, sql functions list pdf, function in sql server, sql functions w3schools, user defined functions in sql ...
SQL Select Statement on W3Schools.com Example Code: Get Column Headers from SQL Query with Database Connectivity Toolkit Other Support Options Ask the NI Community Collaborate with other users in our discussion forums Search the NI Community for a solution Request Support from an Engineer A valid...
**聚合函数(Aggregate Functions)**:计算一组值的汇总信息,如COUNT、SUM、AVG、MAX和MIN。 ```sql SELECT COUNT(*) FROM table_name; SELECT SUM(column_name) FROM table_name; SELECT AVG(column_name) FROM table_name; SELECT MAX(column_name) FROM table_name; SELECT MIN(column_name) FROM table_...