1. The methods generally mentioned on the Internet are as follows:
:=,assignment, such as user_id := 20;
select into assignment, for example
SELECT INTO myrec * FROM emp WHERE empname = myname
2. What I am introducing today is a more general and practical assignment method
select ...into ...
Example of usage:
A variable, select 30 into user_id;
Multiple variables, select 20,30,50 into a,;
3. Into is also commonly used in stored functions (i.e., in stored procedures).
For example, when splicing characters, just enter directly.
select 'update student set remark ='''|| now() ||''' where = '|| $1 into sql_str_run ; execute sql_str_run;
Supplement: Postgresql assignment attention
Assigning values in functions requires attention as follows
Defining variables before beginning
Used when assigning variables:=
Use into assigning values in select
as follows:
create or replace... return i int declare value int; begin value:=100; select id into value from table_name end
The above is personal experience. I hope you can give you a reference and I hope you can support me more. If there are any mistakes or no complete considerations, I would like to give you advice.