SQL 如何在存储过程中使用局部变量？
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时间：2020-09-01 06:22:36 来源:igfitidea点击:
How to use local variables in stored procedures?
提问by ram
if I want to select any id from a table and want to insert it's value in another table as foreign key then how i will do it through stored procedure?
如果我想从表中选择任何 id 并想将它的值作为外键插入另一个表中，那么我将如何通过存储过程来做到这一点？
回答by Neil Knight
An example of how I would approach this.
我将如何处理这个问题的一个例子。
DECLARE @MyID INT;
SET @MyID = 0;
SELECT @MyID = [TableID]
FROM [MyTable]
WHERE [TableID] = 99;
IF @MyID > 0
BEGIN
INSERT INTO [MySecondTable]
VALUES (@MyID, othervalues);
END
回答by pcent
PostgreSQL style variables:
PostgreSQL 样式变量：
DECLARE my_variable1 int;
DECLARE my_variable2 int;
BEGIN
my_variable1 := 25;
SELECT INTO my_variable2 id FROM my_table1;
INSERT INTO my_table2 (my_field1, my_field2, id) VALUES ('XXX', 'YYY', my_variable2);
END;
回答by Will Marcouiller
Oracle style variables:
Oracle 样式变量：
DECLARE v_MyVariable1 NUMBER;
DECLARE v_MyVariable2 VARCHAR2(100);
BEGIN
v_MyVariable1 := 0;
SELECT INTO v_MyVariable2 CUSTOMER_NAME
FROM CUSTOMERS;
SELECT INTO v_MyVariable1 CUSTOMER_HISTORY_SEQ.NEXTVAL FROM DUAL;
INSERT INTO CUSTOMERS_HISTORY (CUSTOMER_ID, CUSTOMER_NAME) VALUES (v_MyVariable1, v_MyVariable2);
EXCEPTION
WHEN OTHERS THEN
NULL;
END;
