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In SQL, you can alias tables and columns. A table alias is called a correlation name, according to the SQL standard. [1] A programmer can use an alias to temporarily assign another name to a table or column for the duration of the current SELECT query. Assigning an alias does not actually rename the column or table.
View all objects within the selected database, empty, rename and drop (delete) objects; Edit table columns, indexes, and foreign keys. Virtual columns on MariaDB servers are supported. Edit view query and settings; Edit procedure SQL body and parameters; Edit trigger SQL body and settings; Edit scheduled event SQL body time settings
In relational databases a virtual column is a table column whose value(s) is automatically computed using other columns values, or another deterministic expression. Virtual columns are defined of SQL:2003 as Generated Column, [1] and are only implemented by some DBMSs, like MariaDB, SQL Server, Oracle, PostgreSQL, SQLite and Firebird (database server) (COMPUTED BY syntax).
Practical query languages have such facilities, e.g. the SQL SELECT allows arithmetic operations to define new columns in the result SELECT unit_price * quantity AS total_price FROM t, and a similar facility is provided more explicitly by Tutorial D's EXTEND keyword. [6] In database theory, this is called extended projection. [7]: 213
Reserved words in SQL and related products In SQL:2023 [3] In IBM Db2 13 [4] In Mimer SQL 11.0 [5] In MySQL 8.0 [6] In Oracle Database 23c [7] In PostgreSQL 16 [1] In Microsoft SQL Server 2022 [2]
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
Microsoft SQL Server: 524,272 TB (32 767 files × 16 TB max file size) 16ZB per instance 524,272 TB 8,060 bytes / 2 TB 6: 1,024 / 30,000(with sparse columns) 2 GB / Unlimited (using RBS/FILESTREAM object) 2 GB 6: 126 bits 2: 0001 9999 128 Microsoft SQL Server Compact (Embedded Database) 4 GB 4 GB 8,060 bytes 1024 2 GB 4000 154 bits 0001 9999 ...
A query includes a list of columns to include in the final result, normally immediately following the SELECT keyword. An asterisk ("*") can be used to specify that the query should return all columns of all the queried tables. SELECT is the most complex statement in SQL, with optional keywords and clauses that include: