Specify additional field characteristics
The following methods set additional characteristics for
fields in the internal data structure:
public void setFieldName (int field, String name) throws SQLException public void setFieldType (int field, int ifxtype) throws SQLException public void setFieldTypeName(int field, String sqltypename) throws SQLException public void setFieldLength(int field, int length) throws SQLException
The field parameter
indicates the field for which the driver should set or obtain a characteristic.
The first field is 1
; the second field is 2
,
and so forth.
The name you specify with setFieldName() appears
in the Java™ class file. The
following example sets the first field name to
IMAGE
.mdata.setFieldName(1, "IMAGE");
The setFieldType() method
sets the data type of a field using a constant from the file com.informix.lang.IfxTypes.
For more information, see Mapping for field types.
The following example specifies the CHAR data type for values in the
third field:
mdata.setFieldType(3, com.informix.lang.IfxTypes.IFX_TYPE_CHAR);
The setFieldTypeName() method
sets the data type of a field using the SQL data type name:
mdata.setFieldTypeName(1, "IMAGE_UDT");
This method is valid only for opaque and distinct types; for other types, the driver ignores the information.
The length parameter
has the following meanings, depending on the data type of the field:
- Character types
- Maximum length in characters
- DATETIME
- Encoded length
- INTERVAL
- Encoded length
- Other data type or no type specified
- Driver ignores the information
The possible values for encoded length are those
in the JDBC 2.20 specification: hour to second; year to second; and
year to fraction(1
), year to fraction(2
),
up through year to fraction(5
).
The following
example specifies that the third (VARCHAR) field in an opaque type
cannot store more than 24 characters:
mdata.setFieldLength(3, 24);