検索CASE構文 - Advanced SQL Engine - Teradata Database

CASE
  when_clause [...]
  [ ELSE statement [...] ]
END CASE ;

when_clause

WHEN conditional_expression THEN statement [...]

statement

{ SQL_statement |
  compound_statement |
  assignment_statement |
  condition_statement |
  [ label_name : ] iteration_statement [ label_name ] |
  ITERATE label_name |
  LEAVE label_name
}

compound_statement

[ label_name : ] BEGIN
  [ local_declaration ] [...]
  [ cursor_declaration ] [...]
  [ condition_handler ] [...]
  [ statement; ] [...]
END [ label_name ] ;

assignment_statement

SET assignment_target = assignment_source

condition_statement

{ CASE_statement | IF_statement }

iteration_statement

{ WHILE conditional_expression
    DO statement; [...] |

  LOOP
    statement; [...]
  END LOOP |

  FOR for_loop_variable AS [ cursor_name CURSOR FOR ] cursor_specification
    DO statement; [...]
  END FOR |

  REPEAT
    statement; [...]
    UNTIL conditional_expression
  END REPEAT
}

local_declaration

DECLARE {
  variable_name [,...] data_type [ DEFAULT { literal | NULL } ] |
  condition_name CONDITION [ FOR SQLSTATE [VALUE] sqlstate_cod ]
} ;

cursor_declaration

DECLARE cursor_name [ [NO] SCROLL ] CURSOR
  [ WITHOUT RETURN |
    WITH RETURN [ONLY] [ TO { CALLER | CLIENT } ]
  ]
  [ FOR { cursor_specification [ FOR { READ ONLY | UPDATE } ] |
          statement_name
        } 
  ] ;

IF_statement

<IF>を参照してください。

CASE_statement

CASE文のいずれかの形式。

condition_handler

DECLARE { CONTINUE | EXIT } HANDLER FOR
  { 
    { SQLSTATE [ VALUE ] sqlstate_code | condition_name } [,...] |

    { SQLEXCEPTION | SQLWARNING | NOT FOUND } [,...]

  } handler_action_statement ;

cursor_specification

SELECT cursor_spec [,...]
  FROM {
    table_name [,...] |

    table_name {
      INNER |
      { LEFT | RIGHT | FULL } OUTER
    } JOIN table_name ON condition
  }

cursor_spec

{ column_name [ [AS] alias_name ] |

  expression [AS] alias_name |

  *
}