Sql 简明教程

SQL - Useful Functions

SQL 有许多用于对字符串或数字数据执行处理的内置函数。以下列出了所有有用的 SQL 内置函数−

SQL has many built-in functions for performing processing on string or numeric data. Following is the list of all useful SQL built-in functions −

  1. SQL COUNT Function - The SQL COUNT aggregate function is used to count the number of rows in a database table.

  2. SQL AVG Function - The SQL AVG aggregate function selects the average value for certain table column.

  3. SQL SUM Function - The SQL SUM aggregate function allows selecting the total for a numeric column.

  4. SQL SQRT Functions - This is used to generate a square root of a given number.

  5. SQL RAND Function - This is used to generate a random number using SQL command.

  6. SQL CONCAT Function - This is used to concatenate any string inside any SQL command.

  7. SQL Numeric Functions - Complete list of SQL functions required to manipulate numbers in SQL.

  8. SQL String Functions - Complete list of SQL functions required to manipulate strings in SQL.