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automatically placing results of a called procedure into a select statement

开发者 https://www.devze.com 2023-01-06 03:32 出处:网络
I\'m playing with some code from an article written by Peter Brawley found here on page 6 of the pdf.I\'m trying to figure out how to automate it so that the result of the procedure is automatically p

I'm playing with some code from an article written by Peter Brawley found here on page 6 of the pdf. I'm trying to figure out how to automate it so that the result of the procedure is automatically placed in the select query. Right now what I am doing is calling the procedure, exporting the result into a text file, going to the text file manually (point click with mouse), copying the result and pasting it into a select statement. I haven't been able to figure out how to either insert the select statement into the procedure, or put the procedure into a table in my database or variable that I can call from the select statement. Any ideas?

Here is the sample code from Peter Brawley, that I've been trying to automate:

use database;
DROP PROCEDURE IF EXISTS writesumpivot;
DELIMITER |
CREATE PROCEDURE writesumpivot(
    db CHAR(64), tbl CHAR(64), pivotcol CHAR(64), sumcol CHAR(64)
)
BEGIN
DECLARE datadelim CHAR(1) DEFAULT '"';
DECLARE comma CHAR(1) DEFAULT ',';
DECLARE singlequote CHAR(1) DEFAULT CHAR(39);
SET @sqlmode = (SELECT @@sql_mode);
SET @@sql_mode='';
SET @pivotstr = CONCAT( 'SELECT DISTINCT CONCAT(', singlequote,
                    ',SUM(IF(', pivotcol, ' = ', datadelim, singlequote,
                    comma, pivotcol, comma, singlequote, datadelim,
                    comma, sumcol, ',0)) AS `',
                    singlequote, comma, pivotcol, comma, singlequote, '`',
                    singlequo开发者_如何学运维te, ') AS sumpivotarg FROM ', db, '.', tbl, 
                    ' WHERE ', pivotcol, ' IS NOT NULL' );
-- UNCOMMENT TO SEE THET MIDLEVEL SQL:
-- SELECT @pivotstr;
PREPARE stmt FROM @pivotstr;
EXECUTE stmt;
drop prepare stmt;
SET @@sql_mode=@sqlmode;
END
|
DELIMITER ;
call writesumpivot('database', 'table', 'pivotcol','sumcol');

Then the Select statement is as follows:

SELECT
    infoField
    [results of the call]
FROM
    database.table
GROUP BY infoField;

Assuming I've ran the call, exported the results, copied them and pasted them into the select statement, my personal results of the call in the SELECT query would look something like this:

SELECT 
    infoField
    ,SUM(IF(pivotcol = "Yellow",sumcol,0)) AS `Yellow`
    ,SUM(IF(pivotcol = "Red",sumcol,0)) AS `Red`
    ,SUM(IF(pivotcol = "Purple",sumcol,0)) AS `Purple`
    ,SUM(IF(pivotcol = "Orange",sumcol,0)) AS `Orange`
    ,SUM(IF(pivotcol = "Green",sumcol,0)) AS `Green`
    ,SUM(IF(pivotcol = "Blue",sumcol,0)) AS `Blue`
    ,SUM(IF(pivotcol = "White",sumcol,0)) AS `White`
FROM database.table
GROUP BY infoField;

Running the above select statement gives me the pivot table that I need. I'm tryig to figure out how to incorporate this into a website, which is why it needs to be automated.

I tried inserting a create table, and then reference the table, but didn't get desired results. Edited the last section of the PROCEDURE as follows:

--SELECT @pivotstr;
DROP TABLE IF EXISTS temp2;
CREATE TABLE IF NOT EXISTS temp2(sumpivotarg varchar(8000));
PREPARE stmt FROM @pivotstr;  
...

changed call and select as follows:

call writesumpivot('database','table','pivotcol','sumcol');
insert into temp2(sumpivotarg) values(@pivotstr);

SELECT 
   table.infoField, temp2.sumpivotarg
FROM table, temp2
GROUP BY infoField

Results from this were the generic code rather than summing the contents of the cells in the database. it looks something like this:

infoField | sumpivotarg <-- Col Headings

123 | SELECT DISTINCT CONCAT('Sum(if(pivotcol=",pivotcol",sumcol,0)) AS'pivotcol,'')..

124 | SELECT DISTINCT CONCAT('Sum(if(pivotcol=",pivotcol",sumcol,0)) AS'pivotcol,'')..

125 | select DISTINCT CONCAT('Sum(if(pivotcol=",pivotcol",sumcol,0)) AS'pivotcol,'')..


I do not mean any disrespect towards mySQL, but this whole writing to a temp table solution for passing tablular data between stored procedures is suboptimal and dangerous (in real world transaction processing). I truly hope that the mySQL team will build in some enterprise level stored procedure functionality. Also, mySQL Functions not being able to return tables is a distinct disadvantage.

I have been slowly moving process over to Linux and mySQL from MSSQL. The short comings of mySQL in the procedure and function department is forcing some major kludgey type rewrites (ala temp tables and globals, etc).

I have been writing SPs for about 20 years (Sybase before SQL Server) and feel strongly that using dynamic SQL does not take advantage of the server side database. Many folks try to implement a Data layer at the client level, but the sever is better suited to this task. It is a natural division of functionality and data. Also, simultaneously running multiple precompiled calls at the server is quite a bit more optimal than repeated calls to the server, for the same processes.

Come on mySQL team, I am keeping my fingers crossed....


You could create a temp table in your DB. Use SQL insert to insert data into temp table as the result of the stored procedure execution. Afterwards you could use that temp table inside your select statement.

Here's an answer that shows how to do that:

Use result set of mysql stored procedure in another stored procedure

Just to mention a similar question:

MySQL How to INSERT INTO temp table FROM Stored Procedure

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