CODIGOHTML=<font color="#AA000" size="30">Sintaxis</font>
<font color="00000" size="15">ALTER TABLE table 
{ [ ALTER COLUMN column_name 
    { new_data_type [ ( precision [ , scale ] ) ] 
        [ COLLATE ' collation_name ' ] 
        [ NULL | NOT NULL ] 
        | {ADD | DROP } ROWGUIDCOL } 
    ] 
    | ADD 
        { [ ' column_definition ' ] 
        | column_name AS computed_column_expression 
        } [ ,...n ] 
    | [ WITH CHECK | WITH NOCHECK ] ADD 
        { ' table_constraint ' } [ ,...n ] 
    | DROP 
        { [ CONSTRAINT ] constraint_name 
            | COLUMN column } [ ,...n ] 
    | { CHECK | NOCHECK } CONSTRAINT 
        { ALL | constraint_name [ ,...n ] } 
    | { ENABLE | DISABLE } TRIGGER 
        { ALL | trigger_name [ ,...n ] } 
}
' column_definition ' ::= 
    { column_name data_type } 
    [ [ DEFAULT constant_expression ] [ WITH VALUES ] 
    | [ IDENTITY [ ( seed , increment ) [ NOT FOR REPLICATION ] ] ] 
        ] 
    [ ROWGUIDCOL ] 
    [ COLLATE ' collation_name ' ] 
    [ ' column_constraint ' ] [ ...n ] 
' column_constraint ' ::= 
    [ CONSTRAINT constraint_name ] 
    { [ NULL | NOT NULL ] 
        | [ { PRIMARY KEY | UNIQUE } 
            [ CLUSTERED | NONCLUSTERED ] 
            [WITH FILLFACTOR = fillfactor] 
            [ ON { filegroup | DEFAULT } ] 
            ] 
        | [ [ FOREIGN KEY ] 
            REFERENCES ref_table [ ( ref_column ) ] 
            [ ON DELETE { CASCADE | NO ACTION } ] 
            [ ON UPDATE { CASCADE | NO ACTION } ] 
            [ NOT FOR REPLICATION ] 
            ] 
        | CHECK [ NOT FOR REPLICATION ] 
            ( logical_expression ) 
    }
' table_constraint ' ::= 
    [ CONSTRAINT constraint_name ] 
    { [ { PRIMARY KEY | UNIQUE } 
        [ CLUSTERED | NONCLUSTERED ] 
        { ( column [ ,...n ] ) } 
        [WITH FILLFACTOR = fillfactor] 
        [ ON { filegroup | DEFAULT } ] 
        ] 
        |    FOREIGN KEY 
            [ ( column [ ,...n ] ) ] 
            REFERENCES ref_table [ ( ref_column [ ,...n ] ) ] 
            [ ON DELETE { CASCADE | NO ACTION } ] 
            [ ON UPDATE { CASCADE | NO ACTION } ] 
            [ NOT FOR REPLICATION ] 
        | DEFAULT constant_expression 
            [ FOR column ] [ WITH VALUES ] 
        |    CHECK [ NOT FOR REPLICATION ] 
            ( search_conditions ) 
    }

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