Get column type using teradata system tables

Question

I want to get the actual column type from teradata system tables like dbc.columns.

This table have column columntype but it does not give the actual datatype.

I can get output with

select type(columnname) from table
output: varchar2(20)

but there are 1000 tables and 50000 columns. Please suggest some query that can give me actual column type of column from metadata itself

Could you be more precise what you mean by "actual column type"? Just a translation of the two character code in dbc.ColumnsV.ColumnType to a string, e.g. CV -> VARCHAR? Or VARCHAR(20), DECIMAL(10,2), etc.? — dnoeth, Feb 10 '14 at 20:46

dnoeth · Answer 1 · 2014-02-17T17:53:21.823

For views the columntype will be NULL, because it's resolved at runtime.

For a single table you can do a HELP COLUMN viewname.*; to get the actual datatypes.

Btw, there's no such type like Varchar2 in Teradata, that's Oracle :-)

Edit: Seems like you want the full definition of a column. This is a SQL UDF returning the same info you find in a SHOW TABLE (I'm not shure if TD14.10 is covered, too, i didn't check, yet):

REPLACE FUNCTION DataTypeString 
 (
  ColumnType CHAR(2),
  ColumnLength INT,
  DecimalTotalDigits SMALLINT,
  DecimalFractionalDigits SMALLINT,
  CharType SMALLINT,
  ColumnUDTName VARCHAR(128) CHARACTER SET UNICODE
 )
RETURNS VARCHAR(60)
LANGUAGE SQL
CONTAINS SQL
DETERMINISTIC
SQL SECURITY DEFINER
COLLATION INVOKER
INLINE TYPE 1
RETURN 
  CASE ColumnType
    WHEN 'BF' THEN 'BYTE('            || TRIM(CAST(ColumnLength AS INTEGER)) || ')'
    WHEN 'BV' THEN 'VARBYTE('         || TRIM(CAST(ColumnLength AS INTEGER)) || ')'
    WHEN 'CF' THEN 'CHAR('            || TRIM(CAST(ColumnLength AS INTEGER)) || ')'
    WHEN 'CV' THEN 'VARCHAR('         || TRIM(CAST(ColumnLength AS INTEGER)) || ')'
    WHEN 'D ' THEN 'DECIMAL('         || TRIM(DecimalTotalDigits) || ','
                                      || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'DA' THEN 'DATE'
    WHEN 'F ' THEN 'FLOAT'
    WHEN 'I1' THEN 'BYTEINT'
    WHEN 'I2' THEN 'SMALLINT'
    WHEN 'I8' THEN 'BIGINT'
    WHEN 'I ' THEN 'INTEGER'
    WHEN 'AT' THEN 'TIME('            || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'TS' THEN 'TIMESTAMP('       || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'TZ' THEN 'TIME('            || TRIM(DecimalFractionalDigits) || ')' || ' WITH TIME ZONE'
    WHEN 'SZ' THEN 'TIMESTAMP('       || TRIM(DecimalFractionalDigits) || ')' || ' WITH TIME ZONE'
    WHEN 'YR' THEN 'INTERVAL YEAR('   || TRIM(DecimalTotalDigits) || ')'
    WHEN 'YM' THEN 'INTERVAL YEAR('   || TRIM(DecimalTotalDigits) || ')'      || ' TO MONTH'
    WHEN 'MO' THEN 'INTERVAL MONTH('  || TRIM(DecimalTotalDigits) || ')'
    WHEN 'DY' THEN 'INTERVAL DAY('    || TRIM(DecimalTotalDigits) || ')'
    WHEN 'DH' THEN 'INTERVAL DAY('    || TRIM(DecimalTotalDigits) || ')'      || ' TO HOUR'
    WHEN 'DM' THEN 'INTERVAL DAY('    || TRIM(DecimalTotalDigits) || ')'      || ' TO MINUTE'
    WHEN 'DS' THEN 'INTERVAL DAY('    || TRIM(DecimalTotalDigits) || ')'      || ' TO SECOND('
                                      || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'HR' THEN 'INTERVAL HOUR('   || TRIM(DecimalTotalDigits) || ')'
    WHEN 'HM' THEN 'INTERVAL HOUR('   || TRIM(DecimalTotalDigits) || ')'      || ' TO MINUTE'
    WHEN 'HS' THEN 'INTERVAL HOUR('   || TRIM(DecimalTotalDigits) || ')'      || ' TO SECOND('
                                      || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'MI' THEN 'INTERVAL MINUTE(' || TRIM(DecimalTotalDigits) || ')'
    WHEN 'MS' THEN 'INTERVAL MINUTE(' || TRIM(DecimalTotalDigits) || ')'      || ' TO SECOND('
                                      || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'SC' THEN 'INTERVAL SECOND(' || TRIM(DecimalTotalDigits) || ',' 
                                      || TRIM(DecimalFractionalDigits) || ')'
    WHEN 'BO' THEN 'BLOB('            || TRIM(CAST(ColumnLength AS INTEGER)) || ')'
    WHEN 'CO' THEN 'CLOB('            || TRIM(CAST(ColumnLength AS INTEGER)) || ')'

    WHEN 'PD' THEN 'PERIOD(DATE)'     
    WHEN 'PM' THEN 'PERIOD(TIMESTAMP('|| TRIM(DecimalFractionalDigits) || ')' || ' WITH TIME ZONE'
    WHEN 'PS' THEN 'PERIOD(TIMESTAMP('|| TRIM(DecimalFractionalDigits) || '))'
    WHEN 'PT' THEN 'PERIOD(TIME('     || TRIM(DecimalFractionalDigits) || '))'
    WHEN 'PZ' THEN 'PERIOD(TIME('     || TRIM(DecimalFractionalDigits) || '))' || ' WITH TIME ZONE'
    WHEN 'UT' THEN COALESCE(ColumnUDTName,  '<Unknown> ' || ColumnType)

    WHEN '++' THEN 'TD_ANYTYPE'
    WHEN 'N'  THEN 'NUMBER('          || CASE WHEN DecimalTotalDigits = -128 THEN '*' ELSE TRIM(DecimalTotalDigits) END
                                      || CASE WHEN DecimalFractionalDigits IN (0, -128) THEN '' ELSE ',' || TRIM(DecimalFractionalDigits) END
                                      || ')'
    WHEN 'A1' THEN COALESCE('SYSUDTLIB.' || ColumnUDTName,  '<Unknown> ' || ColumnType)
    WHEN 'AN' THEN COALESCE('SYSUDTLIB.' || ColumnUDTName,  '<Unknown> ' || ColumnType)

    ELSE '<Unknown> ' || ColumnType
  END 
  || CASE
        WHEN ColumnType IN ('CV', 'CF', 'CO') 
        THEN CASE CharType 
                WHEN 1 THEN ' CHARACTER SET LATIN'
                WHEN 2 THEN ' CHARACTER SET UNICODE'
                WHEN 3 THEN ' CHARACTER SET KANJISJIS'
                WHEN 4 THEN ' CHARACTER SET GRAPHIC'
                WHEN 5 THEN ' CHARACTER SET KANJI1'
                ELSE ''
             END
         ELSE ''
      END
;

yes varcha2(20) may not be but I can see output of select type(CNCT_INFO_PSNLCELLPH_FRMT_NUM) from WIS_V.WIS_WORKER_COMP_DAY_V as VARCHAR(50) moreover for 1000 tables I cannot go and run HELP COLUMN viewname.*; — user1011046, Feb 05 '14 at 20:37
There's no other way but separate statements for each view. Why do you need it for all those views? — dnoeth, Feb 05 '14 at 22:28
there was a unique kind of requirement where I have to match oracle database to teradata database whether all the tables have same number of columns and columns have same width as in oracle. — user1011046, Feb 05 '14 at 22:42
Thanks dnoeth & Sqlab. Just one doubt, some columntype values have values like "----", "?" or null. what does these datatype represent. — user1011046, Feb 17 '14 at 20:22
A NULL indicates it's a column from a view, only the name is stored for those columns — dnoeth, Feb 17 '14 at 22:27

score 3 · Answer 2 · answered Feb 14 '14 at 14:51

I found this statement

SELECT
DATABASENAME, TABLENAME, COLUMNNAME, TRIM(COLUMNTYPE)||'('||TRIM(COLUMNNUM)||')'  
FROM (
  SELECT DATABASENAME, TABLENAME, COLUMNNAME,
  CASE 
    WHEN COLUMNTYPE='CF' THEN 'CHAR'
    WHEN COLUMNTYPE='CV' THEN 'VARCHAR'
    WHEN COLUMNTYPE='D'  THEN 'DECIMAL' 
    WHEN COLUMNTYPE='TS' THEN 'TIMESTAMP'      
    WHEN COLUMNTYPE='I'  THEN 'INTEGER'
    WHEN COLUMNTYPE='I2' THEN 'SMALLINT'
    WHEN COLUMNTYPE='DA' THEN 'DATE'  
  END AS COLUMNTYPE,
  CASE 
    WHEN COLUMNTYPE='CF' THEN COLUMNLENGTH
    WHEN COLUMNTYPE='CV' THEN COLUMNLENGTH
    WHEN COLUMNTYPE='D'  THEN (DECIMALTOTALDIGITS||','||DECIMALFRACTIONALDIGITS)
    WHEN COLUMNTYPE='TS' THEN COLUMNLENGTH     
    WHEN COLUMNTYPE='I'  THEN DECIMALTOTALDIGITS
    WHEN COLUMNTYPE='I2' THEN DECIMALTOTALDIGITS
    WHEN COLUMNTYPE='DA' THEN NULL
  END AS COLUMNNUM
  FROM DBC.COLUMNS
  WHERE DATABASENAME='your database' 
) TBL

score 0 · Answer 3 · edited May 23 '17 at 12:01

Going by Retrieving column and other metadata information in Teradata I'd suggest to extract the names of tables and columns from the DBC tables and then build a 'simple script' to fetch all the information. I have no clue about TD but going from the Quick Reference it shouldn't be too difficult to create a loop that fetches the results dynamically and inserts it in your own table.

Finally a good case for proposing a cursor =)

Get column type using teradata system tables

3 Answers3

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