SQL – CHECK Keyword
The CHECK keyword is a constraint that limits the value that can be placed in a column.
SQL – CONSTRAINT Keyword
The CONSTRAINT keyword is used to create or delete a constraint from an existing table.
SQL – DEFAULT Keyword
The DEFAULT keyword provides a default value for a column that will be added to all new records if no other value is specified.
SQL – DROP Keyword
The DROP keyword is used to delete existing columns, constraints, databases, indexes, tables, and views.
SQL – FOREIGN KEY Keywords
The FOREIGN KEY keywords are a key (a field or fields in one table that refers to the PRIMARY KEY in another table) used to link two tables together.
SQL – INDEX Keyword
Indexes are used to speed up the retrieval of data (searches/queries) from the database.
SQL – PRIMARY KEY Keywords
The PRIMARY KEY keywords uniquely identifies each record in a table, which can have only one primary key consisting of a single field or multiple fields.
SQL – MySQL ACOS() Function
The MySQL ACOS() function returns the arc cosine of a number. The specified number must be between -1 and 1, or NULL will be returned.
SQL – MySQL ADDDATE() Function
The MySQL ADDDATE() function adds a time/date interval to a date and then returns the date.
SQL – MySQL ADDTIME() Function
The MySQL ADDTIME() function adds a time interval to a time/datetime and then returns the time/datetime.
SQL – MySQL ASCII() Function
The MySQL ASCII() function returns the ASCII value for the specific character.
SQL – MySQL ASIN() Function
The MySQL ASIN() function returns the arc sine of a number. The specified number must be between -1 and 1, or NULL will be returned.
SQL – MySQL ATAN() Function
The MySQL ATAN() function returns the arc tangent of one or two numbers.
SQL – MySQL AVG() Function
The MySQL AVG() function returns the average value of an expression (NULL values are ignored).
SQL – MySQL BIN() Function
The MySQL BIN() function returns a binary representation of a number, as a string value.