INSERT with SELECT
I have a query that inserts using a SELECT
state开发者_如何学Cment:
INSERT INTO courses (name, location, gid)
SELECT name, location, gid
FROM courses
WHERE cid = $cid
Is it possible to only select "name, location" for the insert, and set gid
to something else in the query?
Yes, absolutely, but check your syntax.
INSERT INTO courses (name, location, gid)
SELECT name, location, 1
FROM courses
WHERE cid = 2
You can put a constant of the same type as gid
in its place, not just 1, of course. And, I just made up the cid
value.
Yes, it is. You can write :
INSERT INTO courses (name, location, gid)
SELECT name, location, 'whatever you want'
FROM courses
WHERE cid = $ci
or you can get values from another join of the select ...
Correct Syntax: select spelling was wrong
INSERT INTO courses (name, location, gid)
SELECT name, location, 'whatever you want'
FROM courses
WHERE cid = $ci
Sure, what do you want to use for the gid? a static value, PHP var, ...
A static value of 1234 could be like:
INSERT INTO courses (name, location, gid)
SELECT name, location, 1234
FROM courses
WHERE cid = $cid
Of course you can.
One thing should be noted however: The INSERT INTO SELECT
statement copies data from one table and inserts it into another table AND requires that data types in source and target tables match. If data types from given table columns does not match (i.e. trying to insert VARCHAR
into INT
, or TINYINT
intoINT
) the MySQL server will throw an SQL Error (1366)
.
So be careful.
Here is the syntax of the command:
INSERT INTO table2 (column1, column2, column3)
SELECT column1, column2, column3 FROM table1
WHERE condition;
Side note: There is a way to circumvent different column types insertion problem by using casting in your SELECT
, for example:
SELECT CAST('qwerty' AS CHAR CHARACTER SET utf8) COLLATE utf8_bin;
This conversion (CAST()
is synonym of CONVERT()
) is very useful if your tables have different character sets on the same table column (which can potentially lead to data loss if not handled properly).
We all know this works.
INSERT INTO `TableName`(`col-1`,`col-2`)
SELECT `col-1`,`col-2`
===========================
Below method can be used in case of multiple "select" statements. Just for information.
INSERT INTO `TableName`(`col-1`,`col-2`)
select 1,2 union all
select 1,2 union all
select 1,2 ;
The right Syntax for your query is:
INSERT INTO courses (name, location, gid)
SELECT (name, location, gid)
FROM courses
WHERE cid = $cid
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