MySQL How to INSERT INTO [temp table] FROM [Stored Procedure]

Question

This is very similar to question 653714 , but for MySQL instead of SQL Server.

Basically, I have a complicated select that is the basis for several stored procedures. I would like to share the code across the stored procedures, however, I'm not sure how to do this. One way I could do this is by making the shared select a stored procedure and then calling that stored procedure from the other ones. I can't figure out how to work with the result set of the nested stored procedure. If I could put them in a temp table I could use the results effectively, but I can't figure out how to get them in a temp table. For example, this does not work:

CREATE TEMPORARY TABLE tmp EXEC nested_sp();

Answer 1

The problem is, Stored Procedures don't really return output directly. They can execute select statements inside the script, but have no return value.

MySQL calls stored procedures via CALL StoredProcedureName(); And you cannot direct that output to anything, as they don't return anything (unlike a function).

MySQL Call Command

Answer 2

Maybe it's a closed topic, but I would like to offer a solution based on the properties of MySQL temporary tables. First, the way to create the temporary table would not be to call the stored procedure "CREATE TEMPORARY TABLE tmp EXEC nested_sp ();". The query is to the temporary table of "infrastructure", (to name it somehow).

To achieve the desired result, it is necessary to create 2 stored procedures, the first stored procedure processes the data and fills the temporary "infrastructure" table, the second stored procedure, reads this table and continues with the process and finally "DROP" the "infrastructure" table

This is the first stored procedure:

    CREATE DEFINER = 'root'@'localhost'
PROCEDURE cajareal.priv_test()
BEGIN
  CREATE TEMPORARY TABLE IF NOT EXISTS  tmp(
      column1 TEXT
    , column2 TEXT
    , column3 TEXT
    );



  INSERT INTO tmp(column1, column2 , column3) VALUES(CURDATE(), CURRENT_DATE(), CURRENT_TIMESTAMP());

END

This is the second stored procedure:

CREATE DEFINER = 'root'@'localhost'
PROCEDURE cajareal.priv_caller()
BEGIN
  CALL priv_test;

  -- Read data of "infrastructure" table
  SELECT * FROM tmp;


  -- Do the business logic


  -- Delete the "infrastructure" table
  DROP TABLE tmp;
END

I use this technique to analyze a string and convert it to the table

Answer 3

My first reaction was "That sounds like a view to me". Doesn't that abstract it enough so you can just add the variability into an SP per case?

Anything that adds a temp table that wouldn't otherwise be there is a very likely antipattern.

Answer 4

i know this is coming really late but since it took me ages to find a real solution i might as well share. I worked on an example that is below.

the tables created are:

CREATE TABLE BOOK(
B_ID INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY(B_ID),
TITLE VARCHAR(100),
DESCRIPTION VARCHAR(30),
PRICE DOUBLE);

CREATE TABLE BOOK_COMMENT(

PRIMARY KEY(B_C_ID),
B_C_ID INT NOT NULL AUTO_INCREMENT,
REMARK VARCHAR(120),
B_ID INT,
FOREIGN KEY(B_ID) REFERENCES BOOK(B_ID));

CREATE TABLE AUTHOR(
A_ID INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY(A_ID),
A_NAME CHAR(15),
B_ID INT,

FOREIGN KEY(B_ID) REFERENCES BOOK(B_ID));

1. DELIMITER

CREATE PROCEDURE BOOK_IMPORTANT( _PRICE DOUBLE, _B_ID INT, A_NAME CHAR(15), _BD_ID INT)

BEGIN

INSERT INTO BOOK(PRICE)

VALUES(_PRICE);

SET _B_ID=LAST_INSERT_ID();

INSERT INTO BOOK_COMMENT(B_ID)

VALUES(_B_ID);

SET _BD_ID=LAST_INSERT_ID();

INSERT INTO AUTHOR(A_NAME,B_ID)

VALUES(A_NAME,_BD_ID);

END

then use the following to insert the values.

CALL BOOK_IMPORTANT('0.79',LAST_INSERT_ID(),'',LAST_INSERT_ID());

LAST_INSERT_ID() takes the last auto increment of the table and inserts it into the referencing column of the child table.

In the procedure parameters _B_ID and _BD_ID represent the B_ID since I need B_ID as a foreign key in both tables.

Sorry for the excess wording. All the other guys expect you to automatically know how to do it. Hope it helps

Answer 5

You cannot "SELECT INTO" with stored procedures.

Create the temporary table first and have your stored procedure to store the query result into the created temporary table using normal "INSERT INTO". The temporary table is visible as long as you drop it or until the connection is closed.