Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Dynamically checking rules in database tables using SQL
Top Forums Programming Dynamically checking rules in database tables using SQL Post 302846403 by figaro on Friday 23rd of August 2013 06:28:51 PM
Old 08-23-2013
Dynamically checking rules in database tables using SQL
I want to check for rows in a table where all values (except the key) is empty. I am using MySQL 5.5.
I plan to do this mechanically, so the approach should work for any table in my database schema.

Suppose for illustration purposes I start with the following table:
Code:
CREATE TABLE `sources` (
  `source` varchar(3) NOT NULL,
  `description` varchar(24) DEFAULT NULL,
  `pricedata` varchar(24) DEFAULT NULL,
  `tablename` varchar(24) DEFAULT NULL,
  `reference` varchar(64) DEFAULT NULL,
  PRIMARY KEY (`source`)
) DEFAULT CHARSET=latin1;

Then my initial steps are:
Code:
USE information_schema;
SET @myTable = 'sources';
PREPARE statement FROM "SELECT GROUP_CONCAT(column_name SEPARATOR ', ') AS columns FROM columns WHERE table_name = @myTable AND column_key = ' '";
EXECUTE statement;

This yields:
Code:
+----------------------------------------------+
| columns                                      |
+----------------------------------------------+
| description, pricedata, tablename, reference |
+----------------------------------------------+

How do I use this result to be able to construct and execute a statement as follows?:
Code:
SELECT * FROM sources WHERE [description] IS NULL AND [pricedata] IS NULL AND [tablename] IS NULL AND [reference] IS NULL;

That's obviously pseudo-code for illustration purposes, but the idea is that the approach should work for all tables.

I tried something as follows:
Code:
SELECT CONCAT(SELECT * FROM @myTable WHERE ', GROUP_CONCAT(column_name SEPARATOR ' IS NULL AND '), ' IS NULL;) FROM columns WHERE table_name = @myTable;

but that was a little too clever and resulted in an error message. Within the CONCAT a nested prepare-statement might work, but the syntax evades me.

So, how can I dynamically check for rows having all nulls?
 

8 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

writing database tables into a file in unix

I want to collect the database tables(Ex: Emp,Sal,Bonus...etc) in a file & give this file at the command prompt, when prompted for the tables list at command prompt. How can i do that ? Ex:- Import jason/jason1 tables=emp,sal,bonus log=j1.log i want to change this into Ex:- Import... (3 Replies)
Discussion started by: dreams5617
3 Replies

2. Shell Programming and Scripting

Automating back up of database tables

Hi all, i would like to set a cronjob to back up my db tables. I have written the par file, i would like to know how can i execute a exp command in a shell script. my par file userid=admin/password file=backup.dmp log=backupLOG.log tables= (Tables 1, Tables 2)My cron job script will be... (1 Reply)
Discussion started by: new2ss
1 Replies

3. Shell Programming and Scripting

Tables to query to find users for database from shell script

I am coding shell script. I need to connect to different databases like DB2, Oracle and Sybase. I would then need to query tables where it has all the groups, users for that database. I would also need who has what kind of permissions. EG: I know for DB2 some TABAUTH table needs to be... (0 Replies)
Discussion started by: pinnacle
0 Replies

4. Programming

SQL Add to Multiple Tables

I'm pretty new to the database world and I've run into a mental block of sorts. I've been unable to find the answer anywhere. Here's my problem: I have several tables and everything is as normalized as possible (as I've been lead to understand normalization.) Normalization has lead to some... (1 Reply)
Discussion started by: flakblas
1 Replies

5. Shell Programming and Scripting

Passing filename dynamically in SPOOL of SQL*PLUS in shell script

Hi all, I am executing shell script in which I am using SQLLDR In this SQLLDR I am passing text file having PL/SQL script. This script will produce some formated output, this output I have to spool in another text file. Currently I have given this in script file as following Spool... (2 Replies)
Discussion started by: shekharjchandra
2 Replies

6. Programming

Query to join two tables in SQL

Hi, I have 2 tables. Table1 name map_code data_code id aaa 2732C 3333B 10 bbb 1223F 2545v 11 ccc 12 Table2 name map_code data_code id text_description aaa 2732C 3333B 10 description 1 bbb 1223F 2545v 11 ... (3 Replies)
Discussion started by: vanitham
3 Replies

7. Shell Programming and Scripting

Help with database checking script

I haven't coded in ksh in forever and this script is proving me not a great coder. I keep getting unexpected end of file when I try to execute this...Line 94 is the last line of the code.. #!/usr/bin/ksh . /home/oraprod/.bash_profile DBSID=prod # Database sid CONNECTSTR=apps/xxxxxxxx@prod #... (6 Replies)
Discussion started by: kirkladb
6 Replies

8. UNIX for Advanced & Expert Users

Identify tables from Oracle sql scripts

Hi, Please let me know if you have any thoughts on how to read a table that has all the oracle sql files or shell scripts at the job and step level to identify all the tables that does merge, update, delete, insert, create, truncate, alter table (ALTER TABLE XYZ RENAME TO ABC) and call them out... (1 Reply)
Discussion started by: techmoris
1 Replies

LEARN ABOUT PHP

db2_foreign_keys

DB2_FOREIGN_KEYS(3)							 1						       DB2_FOREIGN_KEYS(3)

db2_foreign_keys - Returns a result set listing the foreign keys for a table

SYNOPSIS

       resource db2_foreign_keys (resource  $connection, string  $qualifier, string  $schema, string  $table-name)

DESCRIPTION

	Returns a result set listing the foreign keys for a table.

PARAMETERS

	      o $connection
		- A valid connection to an IBM DB2, Cloudscape, or Apache Derby database.

	      o $qualifier
		- A qualifier for DB2 databases running on OS/390 or z/OS servers. For other databases, pass NULL or an empty string.

	      o $schema
		- The schema which contains the tables. If $schema is NULL, db2_foreign_keys(3) matches the schema for the current connection.

	      o $table-name
		- The name of the table.

RETURN VALUES

	Returns a statement resource with a result set containing rows describing the foreign keys for the specified table. The result set is com-
       posed of the following columns:

       +--------------+---------------------------------------------------+
       | Column name  | 						  |
       |	      | 						  |
       |	      | 		   Description			  |
       |	      | 						  |
       +--------------+---------------------------------------------------+
       | PKTABLE_CAT  | 						  |
       |	      | 						  |
       |	      |  Name of the catalog for the table containing the |
       |	      | primary key. The value is NULL if this table does |
       |	      | not have catalogs.				  |
       |	      | 						  |
       |PKTABLE_SCHEM | 						  |
       |	      | 						  |
       |	      |  Name of the schema for the table containing  the |
       |	      | primary key.					  |
       |	      | 						  |
       |PKTABLE_NAME  | 						  |
       |	      | 						  |
       |	      |   Name of the table containing the primary key.   |
       |	      | 						  |
       |PKCOLUMN_NAME | 						  |
       |	      | 						  |
       |	      |  Name of the column containing the primary key.   |
       |	      | 						  |
       | FKTABLE_CAT  | 						  |
       |	      | 						  |
       |	      |  Name of the catalog for the table containing the |
       |	      | foreign key. The value is NULL if this table does |
       |	      | not have catalogs.				  |
       |	      | 						  |
       |FKTABLE_SCHEM | 						  |
       |	      | 						  |
       |	      |  Name  of the schema for the table containing the |
       |	      | foreign key.					  |
       |	      | 						  |
       |FKTABLE_NAME  | 						  |
       |	      | 						  |
       |	      |   Name of the table containing the foreign key.   |
       |	      | 						  |
       |FKCOLUMN_NAME | 						  |
       |	      | 						  |
       |	      |  Name of the column containing the foreign key.   |
       |	      | 						  |
       |   KEY_SEQ    | 						  |
       |	      | 						  |
       |	      |   1-indexed position of the column in the key.	  |
       |	      | 						  |
       | UPDATE_RULE  | 						  |
       |	      | 						  |
       |	      |  Integer value representing the action applied to |
       |	      | the foreign key when the SQL operation is UPDATE. |
       |	      | 						  |
       | DELETE_RULE  | 						  |
       |	      | 						  |
       |	      |  Integer value representing the action applied to |
       |	      | the foreign key when the SQL operation is DELETE. |
       |	      | 						  |
       |   FK_NAME    | 						  |
       |	      | 						  |
       |	      | 	  The name of the foreign key.		  |
       |	      | 						  |
       |   PK_NAME    | 						  |
       |	      | 						  |
       |	      | 	  The name of the primary key.		  |
       |	      | 						  |
       |DEFERRABILITY | 						  |
       |	      | 						  |
       |	      |  An integer value representing whether	the  for- |
       |	      | eign key deferrability is SQL_INITIALLY_DEFERRED, |
       |	      | SQL_INITIALLY_IMMEDIATE, or SQL_NOT_DEFERRABLE.   |
       |	      | 						  |
       +--------------+---------------------------------------------------+
SEE ALSO

       db2_column_privileges(3),  db2_columns(3),  db2_primary_keys(3),   db2_procedure_columns(3),   db2_procedures(3),   db2_special_columns(3),
       db2_statistics(3), db2_table_privileges(3), db2_tables(3).

PHP Documentation Group 												       DB2_FOREIGN_KEYS(3)
All times are GMT -4. The time now is 05:47 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy