Valid For

Extract and Replicat

Description

Use the GET_COL_METADATA_FROM_NAME function to retrieve column metadata by specifying the name of the desired column. If the character session of the user exit is set with SET_SESSION_CHARSET to a value other than the default character set of the operating system, as defined in ULIB_CS_DEFAULT in the ucharset.h file, the character data that is exchanged between the user exit and the process is interpreted in the session character set.

If the database is case-sensitive, object names must be specified in the same letter case as they are defined in the hosting database; otherwise, the case does not matter.

Syntax

#include "usrdecs.h"
short result_code;
col_metadata_def column_meta_rec;
ERCALLBACK (GET_COL_METADATA_FROM_NAME, &column_meta_rec, &result_code);

Buffer

typedef struct
{
  short column_index;
  char *column_name;
  long max_name_length;
  short native_data_type;
  short gg_data_type;
  short gg_sub_data_type;
  short is_nullable;
  short is_part_of_key;
  short key_column_index;
  short length;
  short precision;
  short scale;
  short source_or_target;
} col_metadata_def;

Input

column_name

The column name of the column value to be returned.

max_name_length

The maximum length of the returned column name. Typically, the maximum length is the length of the name buffer. Since the returned name is null-terminated, the maximum length should equal the maximum length of the column name.

source_or_target

One of the following to indicate whether the source or target record is being compressed.

EXIT_FN_SOURCE_VAL
EXIT_FN_TARGET_VAL

Output

column_index

The column index of the column value to be returned.

actual_name_length

The actual length of the returned name.

source_or_target

One of the following to indicate whether the source or target record is being compressed.

EXIT_FN_SOURCE_VAL
EXIT_FN_TARGET_VAL

value_truncated

A flag (0 or 1) to indicate whether or not the value was truncated. Truncation occurs if the length of the column name plus the null terminator exceeds the maximum buffer length.

native_data_type

The native (to the database) data type of the column.

gg_data_type

The Oracle GoldenGate data type of the column.

gg_sub_data_type

The Oracle GoldenGate sub-type of the column.

is_nullable

Flag indicating whether the column permits a null value (TRUE or FALSE).

is_part_of_key

Flag (TRUE or FALSE) indicating whether the column is part of the key that is being used by Oracle GoldenGate.

key_column_index

Indicates the order of the columns in the index. For example, the following table has two key columns that are defined in one order in the table and another in the index definition.

CREATE TABLE tcustmer
(
cust_code        VARCHAR2(4),
name             VARCHAR2(30),
city             VARCHAR2(20),
state            CHAR(2),
PRIMARY KEY (city, cust_code)
USING INDEX
);

The return is as follows:

• cust_code returns 1

• name returns -1

• city returns 0

• state returns -1

If the column is part of the key, its order in the index is returned as an integer.

If the column is not part of the key, a value of -1 is returned.

length

Returns the length of the column.

precision

If a numeric data type, returns the precision of the column.

scale

If a numeric data type, returns the scale.

Return Values

EXIT_FN_RET_INVALID_PARAM
EXIT_FN_RET_INVALID_CONTEXT
EXIT_FN_RET_EXCEEDED_MAX_LENGTH
EXIT_FN_RET_INVALID_COLUMN
EXIT_FN_RET_OK