varchar to int postgresql

Since the introduction of the relational database model by edugatd in 1970, relational databases began to emerge. After more than 40 years of evolution, today's relational databases have a wide variety of features and are widely used. In the face of

There are a variety of Installation manuals for each platform to be installed. You can search for details in google. Here is the Installation Method On debian, ubuntu class: aptitudeinstallpostgresql # This is the database aptitudeinstallpgadmin3 #

Under Mac, you can use homebrew to install PostgreSQL directly:Brew Install Postgresql-vFor a moment, PostgreSQL will be installed. Next is the initial database, execute the command at the terminal, and initially configure

PostgreSQL tutorial (8): Index details, postgresql Index I. Index type: PostgreSQL provides multiple index types: B-Tree, Hash, GiST, and GIN. Because they use different algorithms, each index type has a suitable Query type, the create index Command

I. Index type:PostgreSQL provides a variety of index types: B-tree, hash, GIST, and gin. Because they use different algorithms, each index type has a suitable Query type, saving time and resources, the create Index Command creates a B-tree index.1.

Postgresql has added the External table access function since 9.1. This function allows the database to directly read files other than the database, such as csv or text files. Postgresql has added the External table access function since 9.1. This

The time can be added and reduced directly in PostgreSQL: Query System Current Time: Select Now ();OrSelect Current_timestamp; SELECT now ():: Timestamp + ' 1 year '; --Current time plus 1 yearsSELECT now ():: Timestamp + ' 1 month '; --Current

Postgresql has added the External table access function since 9.1. This function allows the database to directly read files other than the database, such as csv or text files. DML is not supported for the moment. Postgresql has various plug-ins that

ArticleDirectory Preface Preface PostgreSQL 8.1 was launched. I plan to migrate some SQL server applications to PostgreSQL. The first thing I need to migrate is tables, therefore, we must first figure out the ing relationship between

PostgreSql database artifact FDWIntroduction to FDW of PGHttps://wiki.postgresql.org/wiki/Foreign_data_wrappersThis article briefly introduces the "transparent gateway" from PG to Mysql and PG to Hive ^_^First, install PGInstall the PostgreSQL