HANA SQL Script学习（2）: Data Type Extension

2 Data Type Extension

/*

2.Data Type Extension

--创建table数据类型

CREATE TYPE <type_name> AS TABLE (<column_list_definition>)

 <column_list_definition> ::= <column_elem> [{, <column_elem>}...]

 <column_elem> ::= <column_name> <data_type> [<column_store_data_type>] [<ddic_data_type>]

 <column_name> ::= <identifier>

 <data_type> ::= DATE | TIME | SECONDDATE | TIMESTAMP | TINYINT | SMALLINT | INTEGER | BIGINT | SMALLDECIMAL | DECIMAL

                | REAL | DOUBLE | VARCHAR | NVARCHAR | ALPHANUM | SHORTTEXT | VARBINARY | BLOB | CLOB | NCLOB | TEXT

 <column_store_data_type> ::= CS_ALPHANUM | CS_INT | CS_FIXED | CS_FLOAT | CS_DOUBLE | CS_DECIMAL_FLOAT | CS_FIXED(p-s, s)                          

                           | CS_SDFLOAT | CS_STRING | CS_UNITEDECFLOAT | CS_DATE | CS_TIME | CS_FIXEDSTRING | CS_RAW                           

                           | CS_DAYDATE | CS_SECONDTIME | CS_LONGDATE | CS_SECONDDATE

 <ddic_data_type> ::= DDIC_ACCP | DDIC_ALNM | DDIC_CHAR | DDIC_CDAY | DDIC_CLNT | DDIC_CUKY | DDIC_CURR | DDIC_D16D                   

                           | DDIC_D34D | DDIC_D16R | DDIC_D34R | DDIC_D16S | DDIC_D34S | DDIC_DATS | DDIC_DAY  | DDIC_DEC                  

                           | DDIC_FLTP | DDIC_GUID | DDIC_INT1 | DDIC_INT2 | DDIC_INT4 | DDIC_INT8 | DDIC_LANG | DDIC_LCHR                   

                           | DDIC_MIN  | DDIC_MON  | DDIC_LRAW | DDIC_NUMC | DDIC_PREC | DDIC_QUAN | DDIC_RAW  | DDIC_RSTR                   

                           | DDIC_SEC  | DDIC_SRST | DDIC_SSTR | DDIC_STRG | DDIC_STXT | DDIC_TIMS | DDIC_UNIT | DDIC_UTCM                   

                           | DDIC_UTCL | DDIC_UTCS | DDIC_TEXT | DDIC_VARC | DDIC_WEEK

*/

--示例
CREATE TYPE tt_publishers AS TABLE (
       publisher INTEGER,  
       name VARCHAR(50),  
       price DECIMAL,  
       cnt INTEGER);

--删除table type类型
/*
DROP TYPE <type_name> [<drop_option>]
 <type_name> ::= [<schema_name>.]<identifier>
 <drop_option> ::= CASCADE | RESTRICT
*/
--示例
DROP TYPE tt_publishers;

 

--创建Row Type Variable
DECLARE a ROW (a INT, b VARCHAR(16), c TIMESTAMP);
DECLARE b ROW LIKE <persistent table name>;
DECLARE c ROW LIKE :<other table/row/cursor variable name>;

--注意：
--Row type variables are not supported in scalar user-defined functions.
--EXEC INTO is not supported.
--You cannot pass row type variables as parameters of procedures or functions

--示例,语法报错？？
DO BEGIN
    DECLARE x, y ROW (a INT, b VARCHAR(16), c TIMESTAMP);   
       x = ROW(1, 'a', '2000-01-01');   
       x.a = 2;   
       y = :x;   
       SELECT :y.a, :y.b, :y.c FROM DUMMY;   
       -- Returns [2, 'a', '2000-01-01']
END

DO BEGIN
     DECLARE CURSOR cur FOR SELECT 1 as a, 'a' as b, to_timestamp('2000-01-01') as c FROM DUMMY;   
     DECLARE x ROW LIKE :cur;   
     OPEN cur;   
     FETCH cur INTO x;   
     SELECT :x.a, :x.b, :x.c FROM DUMMY;   
     -- Returns [1, 'a', '2000-01-01']   

     SELECT 2, 'b', '2000-02-02' INTO x FROM DUMMY;   
     SELECT :x.a, :x.b, :x.c FROM DUMMY;   
     -- Returns [2, 'b', '2000-02-02']
 END;