Data Definition Language; defining database structures but not their contents.

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How to determine if a column already exists in a MySQL table before altering the table to add it?

I am trying to determine if a column already exists in a MySQL table before altering the table to add it. I need an all in one query I can run since I am executing this through an old PHP mysql ...
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1answer
38 views

help in correcting the syntax error of the below create table with as with multiple select

Please help to correct the syntax of the below. I am from a math background trying to use Oracle. The command helps me permute the columns and put them in one table. create table newsample AS ( ...
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1answer
47 views

MySQL 5.6 Online DDL lead to to much table-metadata-locks when I just add index

It's normal that table-metadata-lock shows up for a short time when ALTER TABLE t add index ... starts and ends. But I have encountered all DML operations blocked in Waiting for table metadata lock, ...
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1answer
61 views

I really can't get rid of these conditional statements in mysqldump?

My mysqldump DDL file is filled with tons of this: /*!50003 CREATE*/ /*!50017 DEFINER=`root`@`localhost`*/ /*!50003 TRIGGER `my_trigger`... I've searched to no avail for an option to silence this. ...
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1answer
407 views

All users are having NO Privileges in phpMyAdmin

By mistake, I changed all the privileges of user 'root' in my MySQL Database. Not even a single privilege is having for that user. Now if I log in with another user I am able to access only one ...
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1answer
37 views

mysql diff and add diff records into new database

I have two database on two different hosts: host A has database A and table A and host B has database B and table B and now "host A/database A/table A" table A contains records with primary key ...
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1answer
47 views

Trigger to drop table only if there are no records

How do I write a DDL DROP_TABLE trigger that will only drop the table if there are no records?
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1answer
46 views

IS-A relation when defining tables

I already asked this question on SO, prior to realizing that there may have been a more suitable place. I am trying to implement an IS-A relationship between tables. Say I have a singer and a band ...
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1answer
633 views

How to quickly increase column size in Oracle?

In our Oracle 11 database we have a table with more that 100 million rows and we would like to increase size of one column (not used in any index). I tried to execute command alter table shipment ...
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1answer
49 views

Preview the increment in a Mysql table size before running the ALTER TABLE ADD COLUMN statement

Is it possible to preview how much the table size will be incremented by an ALTER TABLE ADD COLUMN statement before running the statement in the database?
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1answer
340 views

Migration script fires 'The data definition language (DDL) command cannot be executed at the Subscriber'

Yesterday I had run a migration script, produced by Visual Studio 2008 schema compare option, on a SQL Server 2008 database. It had run correctly. But today, when I executed the same script, it threw ...
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0answers
87 views

PostgreSQL: Add or drop column under load give wrong number of columns errors

I have a heavily used PostgreSQL database. Sometimes I need to add/remove columns, preferably without any service interruptions. I follow the safe operations list from https://www.braintreepayments....
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307 views

Cannot drop a Postgres table

I want to drop a few tables in my postgresql database. I am able to drop a few tables but there are 3 tables which I am unable to drop. I need to drop a few tables in my Postgres DB. I tried the ...
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0answers
21 views

mysql/mariadb - prepared statement to create schema for users

I have the following scenario: mariaDB (mysql Ver 15.1 Distrib 5.5.49-MariaDB to be exact - I could bug the sysadmins to update if necessary) I want users to be able to create their own, distinct ...
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0answers
28 views

MySQL Cluster “ALTER ONLINE TABLE … STORAGE MEMORY” doubt

I have a MySQL Cluster database where the data is both in-memory and written to disk. I'm trying to understand the ALTER ONLINE TABLE ... STORAGE MEMORY statement, so that I can use this technique to ...
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0answers
55 views

SQL Server Comparison

I am merging two different versions of a database. I want to add some specific fields from source database to destination, so I used Visual Studio to do that. It does the job quite well but only table ...
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0answers
2k views

DDL trigger AFTER ALTER ON SCHEMA behavior

Can anyone please tell me what's going on here: CREATE TRIGGER afr_alt_trig AFTER ALTER ON SCHEMA cols ora_name_list_t; BEGIN IF (ora_dict_obj_type = 'TABLE') THEN select column_name bulk ...
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0answers
187 views

Replication issue - CREATE SELECT alternative?

I've an MySQL 5.1 slave for our BI team. They need to make some CREATE SELECT with big select queries (several million lines). As CREATE SELECT is a DDL, if the replication attempts to update some ...
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0answers
15 views

MySQL Schema Design: One Possible Values Between Multiple Columns

I'm working on a schema for a MySQL database. I have tables which are derivatives of one another. For example, rather than a single "animals" table, I might have separate "mammals" and "birds" tables: ...
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0answers
45 views

Need to find DDLs that were executed in a week in Oracle 11g

Is there any way to find the list of DDLs that were executed in a period of time in a particular schema? It should contain all types of DDLs that were executed on any of the tables of the schema. ...
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0answers
51 views

Slave executing queries with different charset

I need to change a database charset because of this issue and I solved my issue in staging environment with the SQL command ALTER TABLE `articles` CONVERT TO CHARACTER SET utf8 COLLATE ...
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0answers
49 views

Organizing a couple tables in postgresql

I have a data structure that is represented like this: { 'question_id': 1, 'is_required': False, 'question_text': [ { 'id': 1, '...