SQL Constraints : SQL constraints are used to specify rules for data in a table. SQL Create Constraints Constraints can be specified when the table
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SQL NOT NULL Constraint
SQL NOT NULL Constraint : SQL NOT NULL Constraint enforces a column to NOT accept NULL values. By default, a column can hold NULL values. The NOT
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SQL UNIQUE Constraint : SQL UNIQUE Constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee
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SQL PRIMARY KEY Constraint : SQL PRIMARY KEY Constraint uniquely identifies each record in a database table. Primary keys must contain UNIQUE values, and cannot contain
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SQL FOREIGN KEY Constraint : SQL FOREIGN KEY Constraint is a key used to link two tables together. A FOREIGN KEY is a field (or collection
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SQL CHECK Constraint : SQL CHECK Constraint is used to limit the value range that can be placed in a column. If you define a CHECK
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SQL DEFAULT Constraint : SQL DEFAULT Constraint is used to provide a default value for a column. The default value will be added to all new
Read moreSQL CREATE INDEX Statement
SQL CREATE INDEX Statement : SQL CREATE INDEX statement is used to create indexes in tables. Indexes are used to retrieve data from the database very
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SQL AUTO INCREMENT Field : SQL AUTO INCREMENT Field allows a unique number to be generated automatically when a new record is inserted into a table.
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SQL Working With Dates : SQL Working With Dates is the most difficult part when working with dates is to be sure that the format of
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