mysql select variable
For example: SELECT @@GLOBAL.innodb_data_file_path;. Most system variables can be set at server startup ... ,You can store a value in a user-defined variable in one statement and refer to it ... mysql> SET @v3 = CAST(b'1000001' AS UNSIGNED); mysql> SELECT @v1, ... , You'd have to do this with a prepared statement. Something like: SET @s = CONCAT('select * from ', @Cat, ' where ID = ', @ID_1); PREPARE ..., MySQL documentation is quite clear on this: As a general rule, you should never assign a value to a user variable and read the value within the ...,This tutorial shows you how to use the MySQL SELECT INTO variable to store query result in one or more variables. ,MySQL variable assignment You can use either := or = as the assignment operator in the SET statement. For example, the statement assigns number 100 to the variable @counter. SET @counter := 100; The second way to assign a value to a variable is to use the, I ran into this same issue, but I think I know what's causing the confusion. If you use MySql Query Analyzer, you can do this just fine: SELECT ..., The issue is that you cannot mix select and set in one statement, there'll surely be syntax error: select*from t where 1 and set@a=1;. ERROR ...,6, you can assign a value returned by a SELECT statement to a variable, then refer to the variable later in your mysql session. This provides a way to save a result ... ,SET also can be used to assign a SELECT result to a variable, provided that you write the SELECT as a subquery (that is, within parentheses), and it returns a single value. For example: mysql> SET @max_limbs = (SELECT MAX(arms+legs) FROM limbs);
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 mysql select variable 相關參考資料
13.7.7.39 SHOW VARIABLES Statement - MySQL :: Developer ...
For example: SELECT @@GLOBAL.innodb_data_file_path;. Most system variables can be set at server startup ... https://dev.mysql.com 9.4 User-Defined Variables - MySQL :: Developer Zone
You can store a value in a user-defined variable in one statement and refer to it ... mysql> SET @v3 = CAST(b'1000001' AS UNSIGNED); mysql> SELECT @v1, ... https://dev.mysql.com How to select from MySQL where Table name is Variable ...
You'd have to do this with a prepared statement. Something like: SET @s = CONCAT('select * from ', @Cat, ' where ID = ', @ID_1); PREPARE ... https://stackoverflow.com MySQL - Define a variable within select and use it within the ...
MySQL documentation is quite clear on this: As a general rule, you should never assign a value to a user variable and read the value within the ... https://stackoverflow.com MySQL SELECT INTO Variable - MySQL Tutorial
This tutorial shows you how to use the MySQL SELECT INTO variable to store query result in one or more variables. https://www.mysqltutorial.org MySQL Variables - MySQL Tutorial
MySQL variable assignment You can use either := or = as the assignment operator in the SET statement. For example, the statement assigns number 100 to the variable @counter. SET @counter := 100; The s... https://www.mysqltutorial.org SELECT INTO Variable in MySQL DECLARE causes syntax ...
I ran into this same issue, but I think I know what's causing the confusion. If you use MySql Query Analyzer, you can do this just fine: SELECT ... https://stackoverflow.com SET a variable in SELECT statement - MySQL - Stack Overflow
The issue is that you cannot mix select and set in one statement, there'll surely be syntax error: select*from t where 1 and set@a=1;. ERROR ... https://stackoverflow.com Using SQL Variables in Queries - MySQL Cookbook [Book]
6, you can assign a value returned by a SELECT statement to a variable, then refer to the variable later in your mysql session. This provides a way to save a result ... https://www.oreilly.com Using User-Defined Variables in SQL Statements - MySQL ...
SET also can be used to assign a SELECT result to a variable, provided that you write the SELECT as a subquery (that is, within parentheses), and it returns a single value. For example: mysql> SET ... https://www.oreilly.com |