PostgreSQL - 分配变量时出现语法错误？

Question

This is my code:

amount INTEGER;

amount := select count(*) from moneyTable;

I'm getting the following error:

ERROR:   syntax error at or near "select"

Can someone help me out.

Answer 1

From the fine manual :

An assignment of a value to a PL/pgSQL variable is written as:

 variable { := | = } expression; 

but select ... isn't an expression. If you want to assign values from a SELECT to variables, you want to use INTO :

select count(*) into amount from moneyTable;
--              ^^^^^^^^^^^

Answer 2

@mu是简短的答案还是这个

amount := (select count(*) from moneyTable);