Select (SQL) 查询 (SQL)
(重定向自SQL query)
The SQL SELECT statement returns a result set of records from one or more tables.
A SELECT statement retrieves zero or more rows from one or more database tables or database views. In most applications, SELECT
is the most commonly used data manipulation language (DML) command. As SQL is a declarative programming language, SELECT
queries specify a result set, but do not specify how to calculate it. The database translates the query into a "query plan" which may vary between executions, database versions and database software. This functionality is called the "query optimizer" as it is responsible for finding the best possible execution plan for the query, within applicable constraints.