AS for Table¶
Function¶
This statement is used to specify an alias for a table or the subquery result.
Syntax¶
SELECT attr_expr_list FROM table_reference [AS] alias;
Keyword¶
table_reference: Can be a table, view, or subquery.
As: Is used to connect to table_reference and alias. Whether this keyword is added or not does not affect the command execution result.
Precautions¶
The to-be-queried table must exist. Otherwise, an error is reported.
The alias must be specified before execution of the statement. Otherwise, an error is reported. You are advised to specify a unique alias.
Example¶
To specify alias n for table simple_table and visit the name field in table simple_table by using n.name, run the following statement:
SELECT n.score FROM simple_table n WHERE n.name = "leilei";
To specify alias m for the subquery result and return all the query results using SELECT * FROM m, run the following statement:
SELECT * FROM (SELECT * FROM simple_table WHERE score > 90) AS m;