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An SQL UPDATE statement changes the data of one or more records in a table. Either all the rows can be updated, or a subset may be chosen using a condition. The UPDATE statement has the following form: [1] UPDATE table_name SET column_name = value [, column_name = value ...] [WHERE condition]
It also supports >REPLACE INTO syntax, [6] which first attempts an insert, and if that fails, deletes the row, if exists, and then inserts the new one. There is also an IGNORE clause for the INSERT statement, [ 7 ] which tells the server to ignore "duplicate key" errors and go on (existing rows will not be inserted or updated, but all new rows ...
The syntax of the SQL programming language is defined and maintained by ISO/IEC SC 32 as part of ISO/IEC 9075. This standard is not freely available. This standard is not freely available. Despite the existence of the standard, SQL code is not completely portable among different database systems without adjustments.
Row-level trigger: This gets executed before or after any column value of a row changes. Column-level trigger: This gets executed before or after the specified column changes. For each row type: This trigger gets executed once for each row of the result set affected by an insert/update/delete. For each statement type: This trigger gets executed ...
A join clause in the Structured Query Language combines columns from one or more tables into a new table. The operation corresponds to a join operation in relational algebra. Informally, a join stitches two tables and puts on the same row records with matching fields : INNER, LEFT OUTER, RIGHT OUTER, FULL OUTER and CROSS.
A command prompt (or just prompt) is a sequence of (one or more) characters used in a command-line interface to indicate readiness to accept commands. It literally prompts the user to take action. A prompt usually ends with one of the characters $ , % , # , [ 18 ] [ 19 ] : , > or - [ 20 ] and often includes other information, such as the path ...
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 ...
The command-line SQL Plus interface continues in use, mostly [citation needed] for non-interactive scripting or for administrative purposes. The Server Manager Command Line — a replacement of SQL*DBA — is obsolete and SQL Plus 8i and later allows the user to issue statements like STARTUP and SHUTDOWN when connected as SYSDBA.