I generate a dynamic query in My sql Stored procedure. I wanna get the result of this query into a out parameter. How to do this ?
我在My sql Stored过程中生成一个动态查询。我想把这个查询的结果变成一个out参数。这个怎么做 ?
CREATE PROCEDURE 'searchInvoice'
(
OUT numOfRecords INT
)
BEGIN
DECLARE query1 TEXT;
DECLARE query2 TEXT;
SET query1 = 'SELECT COUNT(*) bla bla bla.....';
// Query1 to select the count of matching tuples..
SET query2 = 'SELECT * from bla bla bla....';
// Query2 to select original records...
// later part of this both queries generate dynamically according to some IN parameters..
// now I wanna assign the output of the query1 into numOfRecords
// and I wanna execute the query2 as well.. like this
SET @Sql = query2;
PREPARE STMT FROM @Sql;
EXECUTE STMT;
DEALLOCATE PREPARE STMT;
// output of the query2 can be read in PHP
END
How to get the output of the query1 into OUT parameter(numOfRecords
) ??
如何将query1的输出转换为OUT参数(numOfRecords)?
2 个解决方案
#1
23
Have a look at this example -
看看这个例子 -
CREATE TABLE table1(
column1 VARCHAR(255) DEFAULT NULL,
column2 VARCHAR(255) DEFAULT NULL,
column3 VARCHAR(255) DEFAULT NULL
);
INSERT INTO table1 VALUES
('1', 'value1', 'value2'),
('2', 'value3', 'value4');
DELIMITER $$
CREATE PROCEDURE procedure1(IN Param1 VARCHAR(255), OUT Param2 VARCHAR(255), OUT Param3 VARCHAR(255))
BEGIN
SET @c2 = '';
SET @c3 = '';
SET @query = 'SELECT column2, column3 INTO @c2, @c3 FROM table1 WHERE column1 = ?';
PREPARE stmt FROM @query;
SET @c1 = Param1;
EXECUTE stmt USING @c1;
DEALLOCATE PREPARE stmt;
SET Param2 = @c2;
SET Param3 = @c3;
END$$
DELIMITER ;
-- Call procedure and use variables
SET @Param1 = 2;
SET @Param2 = '';
SET @Param3 = '';
CALL procedure1(@Param1, @Param2, @Param3);
SELECT @Param2, @Param3;
+---------+---------+
| @Param2 | @Param3 |
+---------+---------+
| value3 | value4 |
+---------+---------+
#2
2
select count(*) into @numOfRecords from ....
You have do declare the variable within stored procedure
您已在存储过程中声明变量
I hope I've understood your question.
我希望我理解你的问题。
#1
23
Have a look at this example -
看看这个例子 -
CREATE TABLE table1(
column1 VARCHAR(255) DEFAULT NULL,
column2 VARCHAR(255) DEFAULT NULL,
column3 VARCHAR(255) DEFAULT NULL
);
INSERT INTO table1 VALUES
('1', 'value1', 'value2'),
('2', 'value3', 'value4');
DELIMITER $$
CREATE PROCEDURE procedure1(IN Param1 VARCHAR(255), OUT Param2 VARCHAR(255), OUT Param3 VARCHAR(255))
BEGIN
SET @c2 = '';
SET @c3 = '';
SET @query = 'SELECT column2, column3 INTO @c2, @c3 FROM table1 WHERE column1 = ?';
PREPARE stmt FROM @query;
SET @c1 = Param1;
EXECUTE stmt USING @c1;
DEALLOCATE PREPARE stmt;
SET Param2 = @c2;
SET Param3 = @c3;
END$$
DELIMITER ;
-- Call procedure and use variables
SET @Param1 = 2;
SET @Param2 = '';
SET @Param3 = '';
CALL procedure1(@Param1, @Param2, @Param3);
SELECT @Param2, @Param3;
+---------+---------+
| @Param2 | @Param3 |
+---------+---------+
| value3 | value4 |
+---------+---------+
#2
2
select count(*) into @numOfRecords from ....
You have do declare the variable within stored procedure
您已在存储过程中声明变量
I hope I've understood your question.
我希望我理解你的问题。