How do you set a select statement to a variable in mysql?
Yes, but you need to move the variable assignment into the query: Show
Test case:
Result:
Note that for UPDATE: Further to comments below, you may also do the following: 13.7.4.1 SET Syntax for Variable Assignment
A
The following sections describe
User-Defined Variable AssignmentUser-defined variables are created locally within a session and exist only within the context of that session; see Section 9.4, “User-Defined Variables”. A user-defined variable is written as
Examples:
As demonstrated by those statements, The Performance Schema Parameter and Local Variable Assignment
System Variable Assignment The MySQL server maintains system variables that configure its operation. A system variable can have a global value that
affects server operation as a whole, a session value that affects the current session, or both. Many system variables are dynamic and can be changed at runtime using the If you change a session system variable, the value remains in effect within your session until you change the variable to a different value or the session ends. The change has no effect on other sessions. If you change a global system variable, the value is remembered and used to initialize the session value for new sessions until you change the variable to a different value or the server exits. The change is visible to any client that accesses the global value. However, the change affects the corresponding session value only for clients that connect after the change. The global variable change does not affect the session value for any current client sessions (not even the session within which the global value change occurs). Note Setting a global system variable value always requires special privileges. Setting a session system variable value normally requires no special privileges and can be done by any user, although there are exceptions. For more information, see Section 5.1.8.1, “System Variable Privileges”. The following discussion describes the syntax options for setting system variables:
To set a global system variable value to the compiled-in MySQL default value or a session system variable to the current corresponding global value, set the variable to
the value
To display system variable names and values:
SET Error Handling If any variable assignment in a
Multiple Variable Assignment A
If you set multiple system variables in a single statement, the most recent Examples of multiple-variable assignment:
The
System Variable References in Expressions To refer to the value of a system variable in expressions, use one of the
Note A reference to a system variable in an expression as How do you assign a SELECT statement value to a variable in SQL?When a variable is first declared, its value is set to NULL. To assign a value to a variable, use the SET statement. This is the preferred method of assigning a value to a variable. A variable can also have a value assigned by being referenced in the select list of a SELECT statement.
How do you store a query result into a variable?To store query result in one or more variables, you use the SELECT INTO variable syntax:. SELECT c1, c2, c3, ... ... . SELECT city INTO @city FROM customers WHERE customerNumber = 103;. SELECT @city;. SELECT city, country INTO @city, @country FROM customers WHERE customerNumber = 103;. SELECT @city, @country;. Can you DECLARE a variable in a SELECT statement?Variables in SQL procedures are defined by using the DECLARE statement. Values can be assigned to variables using the SET statement or the SELECT INTO statement or as a default value when the variable is declared. Literals, expressions, the result of a query, and special register values can be assigned to variables.
How do I change the value of a variable in MySQL?To assign a value to a session system variable, precede the variable name by the SESSION or LOCAL keyword, by the @@SESSION. , @@LOCAL. , or @@ qualifier, or by no keyword or no modifier at all: SET SESSION sql_mode = 'TRADITIONAL'; SET LOCAL sql_mode = 'TRADITIONAL'; SET @@SESSION.
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