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  2. Merge (SQL) - Wikipedia

    en.wikipedia.org/wiki/Merge_(SQL)

    Some database implementations adopted the term upsert (a portmanteau of update and insert) to a database statement, or combination of statements, that inserts a record to a table in a database if the record does not exist or, if the record already exists, updates the existing record. This synonym is used in PostgreSQL (v9.5+) [2] and SQLite (v3 ...

  3. Insert (SQL) - Wikipedia

    en.wikipedia.org/wiki/Insert_(SQL)

    An INSERT statement can also be used to retrieve data from other tables, modify it if necessary and insert it directly into the table. All this is done in a single SQL statement that does not involve any intermediary processing in the client application.

  4. Prepared statement - Wikipedia

    en.wikipedia.org/wiki/Prepared_statement

    Major DBMSs, including SQLite, [5] MySQL, [6] Oracle, [7] IBM Db2, [8] Microsoft SQL Server [9] and PostgreSQL [10] support prepared statements. Prepared statements are normally executed through a non-SQL binary protocol for efficiency and protection from SQL injection, but with some DBMSs such as MySQL prepared statements are also available using a SQL syntax for debugging purposes.

  5. SQLite - Wikipedia

    en.wikipedia.org/wiki/SQLite

    SQLite (/ ˌ ɛ s ˌ k juː ˌ ɛ l ˈ aɪ t /, [4] [5] / ˈ s iː k w ə ˌ l aɪ t / [6]) is a database engine written in the C programming language.It is not a standalone app; rather, it is a library that software developers embed in their apps.

  6. Virtual column - Wikipedia

    en.wikipedia.org/wiki/Virtual_column

    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).

  7. SQL syntax - Wikipedia

    en.wikipedia.org/wiki/SQL_syntax

    Each column in an SQL table declares the type(s) that column may contain. ANSI SQL includes the following data types. [14] Character strings and national character strings. CHARACTER(n) (or CHAR(n)): fixed-width n-character string, padded with spaces as needed; CHARACTER VARYING(n) (or VARCHAR(n)): variable-width string with a maximum size of n ...

  8. Database trigger - Wikipedia

    en.wikipedia.org/wiki/Database_trigger

    Before Insert; The four main types of triggers are: 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.

  9. Help:Creating tables - Wikipedia

    en.wikipedia.org/wiki/Help:Creating_tables

    Go to the column you want to replace or fill in (in this table or another one). Be sure visual editor has been launched. If you are copying the whole column including the header cell select just the header cell for that column by clicking on it. Then click "paste" from the edit menu of your browser (or Ctrl+V). You can paste into a blank column ...