ddl

I want to create a database which does not exist through JDBC. Unlike MySQL, PostgreSQL does not support create if not exists syntax. What is the best way to accomplish this? The application does not know if the database exists or not. It should check and if the database exists it should be used. So it makes sense to connect to the desired database and if connection fails due to non-existence of database it should create new database (by connecting to the default postgres database). I checked the error code returned by Postgres but I could not find any relevant code that species the same.

Can anyone tell me how I can generate the DDL for all tables, views, indexes, packages, procedures, functions, triggers, types, sequences, synonyms, grants, etc. inside an Oracle schema? Ideally, I would like to copy the rows too but that is less important. I want to do this on a scheduled job of some kind and not manually each time, so that rules out using the wizard in SQL Developer. Ideally, since I will be running this on several schemas that have grants and synonyms to one another, I would like to have a way to do a find/replace in the output so the schema names match whatever the names

I have heard the terms DDL and DML in reference to databases, but I don't understand what they are. What are they and how do they relate to SQL? DDL is Data Definition Language : it is used to define data structures . For example, with SQL, it would be instructions such as create table , alter table , ... DML is Data Manipulation Language : it is used to manipulate data itself . For example, with SQL, it would be instructions such as insert , update , delete , ... More information see here: MySQL What is DDL, DML and DCL? , the original is as follows: DDL DDL is short name of Data Definition

In a Postgres 9.3 table I have an integer as primary key with automatic sequence to increment, but I have reached the maximum for integer . How to convert it from integer to serial ? I tried: ALTER TABLE my_table ALTER COLUMN id SET DATA TYPE bigint; But the same does not work with the data type serial instead of bigint . Seems like I cannot convert to serial ? Erwin Brandstetter serial is a pseudo data type, not an actual data type. It's an integer underneath with some additional DDL commands executed automatically: Create a sequence (with matching name by default). Set the column NOT NULL

I know that PostgreSQL tables that use a SERIAL primary key end up with an implicit index, sequence and constraint being created by PostgreSQL. The question is how to rename these implicit objects when the table is renamed. Below is my attempt at figuring this out with specific questions at the end. Given a table such as: CREATE TABLE foo ( pkey SERIAL PRIMARY KEY, value INTEGER ); Postgres outputs: NOTICE: CREATE TABLE will create implicit sequence "foo_pkey_seq" for serial column "foo.pkey" NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "foo_pkey" for table "foo" Query

I have a table that has column names like 25, 50, 100, etc.. When trying to update the table I get an error, no matter how I do it UPDATE table SET '25'='100' WHERE id = '1' I have tried quoting and backticking every which way but without success. The error is always along the lines of: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''25'=100 WHERE id=1' at line 1 If I change the column name to twentyfive - I don't have a problem, but that's not what I want. Is it possible to use a number as a column name?

I am working on a program that issues DDL. I would like to know whether CREATE TABLE and similar DDL can be rolled back in Postgres MySQL SQLite et al Describe how each database handles transactions with DDL. joeforker http://wiki.postgresql.org/wiki/Transactional_DDL_in_PostgreSQL:_A_Competitive_Analysis provides an overview of this issue from PostgreSQL's perspective. Is DDL transactional according to this document? PostgreSQL - yes MySQL - no; DDL causes an implicit commit Oracle Database 11g Release 2 and above - by default, no, but an alternative called edition-based redefinition exists