if exists in postgresql

Comparison between PostgreSQL and MySQL Features MySQL PostgreSQL Instance Run the MySQL Command (mysqld) to start the instance. One instance can manage one or more databases. One server can run multiple mysqld instances.

Recently prepared for PostgreSQL database development related knowledge, this article summarizes the PPT content through the blog record sharing, this essay's main content is to introduce the PostgreSQL database basic information, and how to use the

From: http://bbs.chinaunix.net/thread-1688208-1-1.html Features MySQL PostgreSQL Instance Run the MySQL Command (mysqld) to start the instance. One instance can manage one or more databases. One server can run

Installing PostgreSQL using RPM packages in Linux Postgresql and MySQL are currently popular and active open source relational database systems. Compared with high-end Oracle commercial products, Postgresql and MyQL have much room for improvement in

In this article, we use the MySQL 4.0.2-alpha to compare with PostgreSQL 7.2, because the MySQL 4.0.2-alpha begins to support the concept of the transaction, so this comparison is more advantageous for MySQL. We don't want to be just a performance

Goodbye to MongoDB, hello PostgreSQL Olery was founded almost five years ago. It started with the single product (Olery Reputation) developed by Ruby proxy. Over time, we began to work on a series of different products and applications. Today, our

Since MySQL was acquired by Oracle, PostgreSQL has become the first choice for open-source relational databases.This article describes the installation and basic usage of PostgreSQL for first-time users to get started. The following is based on the

In-depth interpretation of sequences in PostgreSQL and their related functions, and interpretation of postgresql I. Introduction A sequence object (also called a SEQUENCE generator) is a special single-row table created using create sequence. A

Ubuntu 9.1 and postgresql are installed in the source code Gisgraphy is required for the project. However, gisgraphy3.0 only supports postgis1.5. therefore, only the old versions of posgresql and postgis can be installed. You can see postgresql

Select EXISTS (select 1 from information_schema.schemata WHERE schema_name = ' Data_2014_shanxi ');Select EXISTS (select 1 from pg_namespace WHERE nspname = ' Data_2014_shanx ');Either way, the second one is more efficient.For detailed analysis, see: