Sintassi SQL ALTER TABLE – Elencato da DBMS

Questo articolo elenca l'SQL ALTER TABLE sintassi, come implementato da vari sistemi di gestione di database (DBMS). La sintassi è elencata esattamente come l'ha elencata ogni fornitore sul proprio sito Web. Fare clic sul collegamento applicabile per visualizzare maggiori dettagli sulla sintassi per un particolare fornitore.

I DBMS coperti sono MySQL, SQL Server, PostgreSQL e Oracle Database.

MySQL

Dal manuale di riferimento di MySQL 5.7:

ALTER [IGNORE] TABLE tbl_name
    [alter_specification [, alter_specification] ...]
    [partition_options]

alter_specification:
    table_options
  | ADD [COLUMN] col_name column_definition
        [FIRST | AFTER col_name ]
  | ADD [COLUMN] (col_name column_definition,...)
  | ADD {INDEX|KEY} [index_name]
        [index_type] (index_col_name,...) [index_option] ...
  | ADD [CONSTRAINT [symbol]] PRIMARY KEY
        [index_type] (index_col_name,...) [index_option] ...
  | ADD [CONSTRAINT [symbol]]
        UNIQUE [INDEX|KEY] [index_name]
        [index_type] (index_col_name,...) [index_option] ...
  | ADD FULLTEXT [INDEX|KEY] [index_name]
        (index_col_name,...) [index_option] ...
  | ADD SPATIAL [INDEX|KEY] [index_name]
        (index_col_name,...) [index_option] ...
  | ADD [CONSTRAINT [symbol]]
        FOREIGN KEY [index_name] (index_col_name,...)
        reference_definition
  | ALGORITHM [=] {DEFAULT|INPLACE|COPY}
  | ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT}
  | CHANGE [COLUMN] old_col_name new_col_name column_definition
        [FIRST|AFTER col_name]
  | LOCK [=] {DEFAULT|NONE|SHARED|EXCLUSIVE}
  | MODIFY [COLUMN] col_name column_definition
        [FIRST | AFTER col_name]
  | DROP [COLUMN] col_name
  | DROP PRIMARY KEY
  | DROP {INDEX|KEY} index_name
  | DROP FOREIGN KEY fk_symbol
  | DISABLE KEYS
  | ENABLE KEYS
  | RENAME [TO|AS] new_tbl_name
  | RENAME {INDEX|KEY} old_index_name TO new_index_name
  | ORDER BY col_name [, col_name] ...
  | CONVERT TO CHARACTER SET charset_name [COLLATE collation_name]
  | [DEFAULT] CHARACTER SET [=] charset_name [COLLATE [=] collation_name]
  | DISCARD TABLESPACE
  | IMPORT TABLESPACE
  | FORCE
  | {WITHOUT|WITH} VALIDATION
  | ADD PARTITION (partition_definition)
  | DROP PARTITION partition_names
  | DISCARD PARTITION {partition_names | ALL} TABLESPACE
  | IMPORT PARTITION {partition_names | ALL} TABLESPACE
  | TRUNCATE PARTITION {partition_names | ALL}
  | COALESCE PARTITION number
  | REORGANIZE PARTITION partition_names INTO (partition_definitions)
  | EXCHANGE PARTITION partition_name WITH TABLE tbl_name [{WITH|WITHOUT} VALIDATION]
  | ANALYZE PARTITION {partition_names | ALL}
  | CHECK PARTITION {partition_names | ALL}
  | OPTIMIZE PARTITION {partition_names | ALL}
  | REBUILD PARTITION {partition_names | ALL}
  | REPAIR PARTITION {partition_names | ALL}
  | REMOVE PARTITIONING
  | UPGRADE PARTITIONING

index_col_name:
    col_name [(length)] [ASC | DESC]

index_type:
    USING {BTREE | HASH}

index_option:
    KEY_BLOCK_SIZE [=] value
  | index_type
  | WITH PARSER parser_name
  | COMMENT 'string'

table_options:
    table_option [[,] table_option] ...  

table_option:
    ENGINE [=] engine_name
  | AUTO_INCREMENT [=] value
  | AVG_ROW_LENGTH [=] value
  | [DEFAULT] CHARACTER SET [=] charset_name
  | CHECKSUM [=] {0 | 1}
  | [DEFAULT] COLLATE [=] collation_name
  | COMMENT [=] 'string'
  | COMPRESSION [=] {'ZLIB'|'LZ4'|'NONE'}
  | CONNECTION [=] 'connect_string'
  | DATA DIRECTORY [=] 'absolute path to directory'
  | DELAY_KEY_WRITE [=] {0 | 1}
  | ENCRYPTION [=] {'Y' | 'N'}
  | INDEX DIRECTORY [=] 'absolute path to directory'
  | INSERT_METHOD [=] { NO | FIRST | LAST }
  | KEY_BLOCK_SIZE [=] value
  | MAX_ROWS [=] value
  | MIN_ROWS [=] value
  | PACK_KEYS [=] {0 | 1 | DEFAULT}
  | PASSWORD [=] 'string'
  | ROW_FORMAT [=] {DEFAULT|DYNAMIC|FIXED|COMPRESSED|REDUNDANT|COMPACT}
  | STATS_AUTO_RECALC [=] {DEFAULT|0|1}
  | STATS_PERSISTENT [=] {DEFAULT|0|1}
  | STATS_SAMPLE_PAGES [=] value
  | TABLESPACE tablespace_name
  | UNION [=] (tbl_name[,tbl_name]...)

partition_options:
    PARTITION BY
        { [LINEAR] HASH(expr)
        | [LINEAR] KEY [ALGORITHM={1|2}] (column_list)
        | RANGE{(expr) | COLUMNS(column_list)}
        | LIST{(expr) | COLUMNS(column_list)} }
    [PARTITIONS num]
    [SUBPARTITION BY
        { [LINEAR] HASH(expr)
        | [LINEAR] KEY [ALGORITHM={1|2}] (column_list) }
      [SUBPARTITIONS num]
    ]
    [(partition_definition [, partition_definition] ...)]

partition_definition:
    PARTITION partition_name
        [VALUES 
            {LESS THAN {(expr | value_list) | MAXVALUE} 
            | 
            IN (value_list)}]
        [[STORAGE] ENGINE [=] engine_name]
        [COMMENT [=] 'comment_text' ]
        [DATA DIRECTORY [=] 'data_dir']
        [INDEX DIRECTORY [=] 'index_dir']
        [MAX_ROWS [=] max_number_of_rows]
        [MIN_ROWS [=] min_number_of_rows]
        [TABLESPACE [=] tablespace_name] 
        [(subpartition_definition [, subpartition_definition] ...)]

subpartition_definition:
    SUBPARTITION logical_name
        [[STORAGE] ENGINE [=] engine_name]
        [COMMENT [=] 'comment_text' ]
        [DATA DIRECTORY [=] 'data_dir']
        [INDEX DIRECTORY [=] 'index_dir']
        [MAX_ROWS [=] max_number_of_rows]
        [MIN_ROWS [=] min_number_of_rows]
        [TABLESPACE [=] tablespace_name] 

SQL Server

Dal riferimento Transact-SQL:

ALTER TABLE [ database_name . [ schema_name ] . | schema_name . ] table_name 
{ 
    ALTER COLUMN column_name 
    { 
        [ type_schema_name. ] type_name [ ( { precision [ , scale ] 
            | max | xml_schema_collection } ) ] 
        [ COLLATE collation_name ] 
        [ NULL | NOT NULL ] [ SPARSE ]

    | {ADD | DROP } 
        { ROWGUIDCOL | PERSISTED | NOT FOR REPLICATION | SPARSE }
    } 
        | [ WITH { CHECK | NOCHECK } ]

    | ADD 
    { 
        <column_definition>
      | <computed_column_definition>
      | <table_constraint> 
      | <column_set_definition> 
    } [ ,...n ]

    | DROP 
     {
         [ CONSTRAINT ] 
         { 
              constraint_name 
              [ WITH 
               ( <drop_clustered_constraint_option> [ ,...n ] ) 
              ] 
          } [ ,...n ]
          | COLUMN 
          {
              column_name 
          } [ ,...n ]
     } [ ,...n ]
    | [ WITH { CHECK | NOCHECK } ] { CHECK | NOCHECK } CONSTRAINT 
        { ALL | constraint_name [ ,...n ] } 

    | { ENABLE | DISABLE } TRIGGER 
        { ALL | trigger_name [ ,...n ] }

    | { ENABLE | DISABLE } CHANGE_TRACKING 
        [ WITH ( TRACK_COLUMNS_UPDATED = { ON | OFF } ) ]

    | SWITCH [ PARTITION source_partition_number_expression ]
        TO target_table 
        [ PARTITION target_partition_number_expression ]

    | SET ( FILESTREAM_ON = { partition_scheme_name | filegroup | 
                "default" | "NULL" } )

    | REBUILD 
      [ [PARTITION = ALL]
        [ WITH ( <rebuild_option> [ ,...n ] ) ] 
      | [ PARTITION = partition_number 
           [ WITH ( <single_partition_rebuild_option> [ ,...n ] ) ]
        ]
      ]

    | <table_option>

    | <filetable_option>

}
[ ; ]

Opzioni

<column_set_definition> ::= 
    column_set_name XML COLUMN_SET FOR ALL_SPARSE_COLUMNS

<drop_clustered_constraint_option> ::=  
    { 
        MAXDOP = max_degree_of_parallelism 
      | ONLINE = {ON | OFF }
      | MOVE TO { partition_scheme_name ( column_name ) | filegroup
          | "default" }
    }
<table_option> ::=
    {
        SET ( LOCK_ESCALATION = { AUTO | TABLE | DISABLE } )
    }

<filetable_option> ::=
    {
       [ { ENABLE | DISABLE } FILETABLE_NAMESPACE ]
       [ SET ( FILETABLE_DIRECTORY = directory_name ) ]
    }
<single_partition_rebuild__option> ::=
{
      SORT_IN_TEMPDB = { ON | OFF }
    | MAXDOP = max_degree_of_parallelism
    | DATA_COMPRESSION = { NONE | ROW | PAGE} }
}

PostgreSQL

Dal manuale di PostgreSQL 9.5:

ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]
    action [, ... ]
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]
    RENAME [ COLUMN ] column_name TO new_column_name
ALTER TABLE [ IF EXISTS ] [ ONLY ] name [ * ]
    RENAME CONSTRAINT constraint_name TO new_constraint_name
ALTER TABLE [ IF EXISTS ] name
    RENAME TO new_name
ALTER TABLE [ IF EXISTS ] name
    SET SCHEMA new_schema
ALTER TABLE ALL IN TABLESPACE name [ OWNED BY role_name [, ... ] ]
    SET TABLESPACE new_tablespace [ NOWAIT ]

where action is one of:

    ADD [ COLUMN ] column_name data_type [ COLLATE collation ] [ column_constraint [ ... ] ]
    DROP [ COLUMN ] [ IF EXISTS ] column_name [ RESTRICT | CASCADE ]
    ALTER [ COLUMN ] column_name [ SET DATA ] TYPE data_type [ COLLATE collation ] [ USING expression ]
    ALTER [ COLUMN ] column_name SET DEFAULT expression
    ALTER [ COLUMN ] column_name DROP DEFAULT
    ALTER [ COLUMN ] column_name { SET | DROP } NOT NULL
    ALTER [ COLUMN ] column_name SET STATISTICS integer
    ALTER [ COLUMN ] column_name SET ( attribute_option = value [, ... ] )
    ALTER [ COLUMN ] column_name RESET ( attribute_option [, ... ] )
    ALTER [ COLUMN ] column_name SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
    ADD table_constraint [ NOT VALID ]
    ADD table_constraint_using_index
    ALTER CONSTRAINT constraint_name [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]
    VALIDATE CONSTRAINT constraint_name
    DROP CONSTRAINT [ IF EXISTS ]  constraint_name [ RESTRICT | CASCADE ]
    DISABLE TRIGGER [ trigger_name | ALL | USER ]
    ENABLE TRIGGER [ trigger_name | ALL | USER ]
    ENABLE REPLICA TRIGGER trigger_name
    ENABLE ALWAYS TRIGGER trigger_name
    DISABLE RULE rewrite_rule_name
    ENABLE RULE rewrite_rule_name
    ENABLE REPLICA RULE rewrite_rule_name
    ENABLE ALWAYS RULE rewrite_rule_name
    DISABLE ROW LEVEL SECURITY
    ENABLE ROW LEVEL SECURITY
    FORCE ROW LEVEL SECURITY
    NO FORCE ROW LEVEL SECURITY
    CLUSTER ON index_name
    SET WITHOUT CLUSTER
    SET WITH OIDS
    SET WITHOUT OIDS
    SET TABLESPACE new_tablespace
    SET { LOGGED | UNLOGGED }
    SET ( storage_parameter = value [, ... ] )
    RESET ( storage_parameter [, ... ] )
    INHERIT parent_table
    NO INHERIT parent_table
    OF type_name
    NOT OF
    OWNER TO { new_owner | CURRENT_USER | SESSION_USER }
    REPLICA IDENTITY { DEFAULT | USING INDEX index_name | FULL | NOTHING }

and table_constraint_using_index is:

    [ CONSTRAINT constraint_name ]
    { UNIQUE | PRIMARY KEY } USING INDEX index_name
    [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

Database Oracle

Dalla documentazione online di Oracle Database 12c Versione 1 (12.1):

ALTER TABLE [ schema. ] table
  [ alter_table_properties
  | column_clauses
  | constraint_clauses
  | alter_table_partitioning
  | alter_external_table
  | move_table_clause
  | modify_opaque_type
  ]
  [ enable_disable_clause
  | { ENABLE | DISABLE } { TABLE LOCK | ALL TRIGGERS }
  ] ...
  ;

Quanto segue delinea il dettaglio delle varie opzioni.

alter_table_properties::=

{ { { physical_attributes_clause
    | logging_clause
    | table_compression
    | inmemory_alter_table_clause
    | ilm_clause
    | supplemental_table_logging
    | allocate_extent_clause
    | deallocate_unused_clause
    | { CACHE | NOCACHE }
    | RESULT_CACHE ( MODE {DEFAULT | FORCE} )
    | upgrade_table_clause
    | records_per_block_clause
    | parallel_clause
    | row_movement_clause
    | flashback_archive_clause
    }...
  | RENAME TO new_table_name
  } [ alter_iot_clauses ] [ alter_XMLSchema_clause ]
| { shrink_clause 
  | READ ONLY
  | READ WRITE 
  | REKEY encryption_spec 
  | [NO] ROW ARCHIVAL
  | ADD attribute_clustering_clause
  | MODIFY CLUSTERING [ clustering_when ] [ zonemap_clause ]
  | DROP CLUSTERING
  }
}

clausole_colonna::=

{ { add_column_clause
  | modify_column_clauses
  | drop_column_clause
  | add_period_clause
  | drop_period_clause
  }...
| rename_column_clause
| { modify_collection_retrieval }...
| { modify_LOB_storage_clause }...
| { alter_varray_col_properties }...
}

clausole_di_vincolo::=

{ ADD { { out_of_line_constraint }...
      | out_of_line_REF_constraint
      }
| MODIFY { CONSTRAINT constraint_name
         | PRIMARY KEY
         | UNIQUE (column [, column ]...)
         } constraint_state [ CASCADE ]
| RENAME CONSTRAINT old_name TO new_name
| { drop_constraint_clause }...
}

alter_table_partitioning ::=

{ modify_table_default_attrs
| alter_interval_partitioning
| set_subpartition_template
| modify_table_partition
| modify_table_subpartition
| move_table_partition
| move_table_subpartition
| add_table_partition
| coalesce_table_partition
| drop_table_partition
| drop_table_subpartition
| rename_partition_subpart
| truncate_partition_subpart
| split_table_partition
| split_table_subpartition
| merge_table_partitions
| merge_table_subpartitions
| exchange_partition_subpart
}

alter_external_table ::=

{ add_column_clause
| modify_column_clauses
| drop_column_clause
| parallel_clause
| external_data_properties
| REJECT LIMIT { integer | UNLIMITED }
| PROJECT COLUMN { ALL | REFERENCED }
}
  [ add_column_clause
  | modify_column_clauses
  | drop_column_clause
  | parallel_clause
  | external_data_properties
  | REJECT LIMIT { integer | UNLIMITED }
  | PROJECT COLUMN { ALL | REFERENCED }
  ]...

move_table_clause ::=

MOVE [ ONLINE ]
   [ segment_attributes_clause ]
   [ table_compression ]
   [ index_org_table_clause ]
   [ { LOB_storage_clause | varray_col_properties }... ]
   [ parallel_clause ]
   [ allow_disallow_clustering ]

modify_opaque_type::=

MODIFY OPAQUE TYPE anydata_column
STORE ( type_name [, type_name ]... ) UNPACKED

enable_disable_clause::=

{ ENABLE | DISABLE }
[ VALIDATE | NOVALIDATE ]
{ UNIQUE (column [, column ]...)
| PRIMARY KEY
| CONSTRAINT constraint_name
}
[ using_index_clause ]
[ exceptions_clause ]
[ CASCADE ]
[ { KEEP | DROP } INDEX ]

Per i dettagli sulle sottoclausole dei vari componenti, vedere la documentazione ufficiale di Oracle.

Utilizzo della GUI

La modifica delle tabelle può essere eseguita anche tramite la GUI in ciascuno dei sistemi di gestione del database o utilizzando uno qualsiasi degli strumenti GUI disponibili per l'uso con quel prodotto.

Ad esempio, MySQL Workbench può essere utilizzato con MySQL.