Rarely used.ģ) INFORMATION_SCHEMA, used by the Information Schema ViewsĤ) sys, reserved for SQL Server internal use exclusively There are several built-in database schemas, and they can't be dropped or altered:Ģ) guest contains objects available to a guest user ("guest user" is a special role in SQL Server lingo, with some default and highly restricted permissions). The tables that are allocated to a specific domain are displayed in SQL Server Studio Manager with the schema name prepended to the table name (exactly the same as the tables that belong to the default dbo schema). That helps to organize the database.įor example, you can create an schema called sales, with tables such as invoices, creditorders (and any other related with sales), and another schema called lookup, with tables such as countries, currencies, subscriptiontypes (and any other table used as look up table). Now, SQL server allows the creation of different schema, which gives you the possibility of grouping tables that share a similar purpose. When you query a table that hasn't been allocated to any particular schema, you can do something like: SELECT * It's a container or namespace ( Querying Microsoft SQL Server 2012)īy default, all the tables in SQL Server belong to a default schema called dbo. In SQL server:,Įvery table belongs to a grouping of objects in the database called database schema. However, this is not the case in other database engines such as SQL Server. Strictly speaking, the difference between Database and Schema is inexisting in MySql. Views) to implement their equivalent of "schema".Īs far as administration is concerned, this should not matter too much,īecause here you have differences anyway.Īs far as you look at application code, you "only" have to care aboutĬases where one application accesses tables from multiple name spaces.Īnd for this it should not matter whether the name space is that of a "user" or a "CREATE USER" command, so there were products that used theĬoncept of a "user" (who then had his own name space for tables and OTOH, ISTR this version of the standard did not have the concept of a Some cross-schema access to tables and views, but I assume it did.ĪFAIR, no product (at least back then) really implemented it, that whole I do not know whether that version defined All tables and views wereĬreated within a "schema". Multiple name spaces for table and view names. That standard had a "CREATE SCHEMA" command, and it served to introduce This all goes back to an ANSI standard for SQL in the mid-80s. Mysql documentation says : CREATE SCHEMA is a synonym for CREATE DATABASE as of MySQL 5.0.2.
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