TRANSLATE ... USING

Examples

The following statement translates a license number. All letters ’ABC...Z’ are translated to ’X’ and all digits ’012 . . . 9’ are translated to ’9’:

SELECT TRANSLATE(’2KRW229’, ’0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ’, ’9999999999XXXXXXXXXXXXXXXXXXXXXXXXXX’) "License"

FROM DUAL;

License

--------

9XXX999

The following statement returns a license number with the characters removed and the digits remaining:

SELECT TRANSLATE(’2KRW229’, ’0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ’, ’0123456789’) "Translate example"

FROM DUAL;

Translate example

-----------------

2229

TRANSLATE ... USING

Syntax translate_using::=

Purpose

TRANSLATE ... USING converts text into the character set specified for conversions between the database character set and the national character set.

Functions 6-189

TRANSLATE ... USING

Note: The TRANSLATE ... USING function is supported primarily for ANSI compatibility. Oracle Corporation recommends that you use the TO_CHAR and TO_NCHAR functions, as appropriate, for converting data to the database or national character set. TO_CHAR and TO_NCHAR can take as arguments a greater variety of datatypes than TRANSLATE ... USING, which accepts only character data.

The text argument is the expression to be converted.

■Specifying the USING CHAR_CS argument converts text into the database character set. The output datatype is VARCHAR2.

■Specifying the USING NCHAR_CS argument converts text into the national character set. The output datatype is NVARCHAR2.

This function is similar to the Oracle CONVERT function, but must be used instead of CONVERT if either the input or the output datatype is being used as NCHAR or NVARCHAR2. If the input contains UCS2 codepoints or backslash characters (\), then use the UNISTR function.

See Also: CONVERT on page 6-36 and UNISTR on page 6-196

Examples

The following statements use data from the sample table oe.product_ descriptions to show the use of the TRANSLATE ... USING function:

CREATE TABLE translate_tab (char_col VARCHAR2(100), nchar_col NVARCHAR2(50));

INSERT INTO translate_tab SELECT NULL, translated_name

FROM product_descriptions WHERE product_id = 3501;

SELECT * FROM translate_tab;

CHAR_COL NCHAR_COL

------------------------- -------------------------

...

C per a SPNIX4.0 - Sys C pro SPNIX4.0 - Sys

C for SPNIX4.0 - Sys C til SPNIX4.0 - Sys

...

6-190 Oracle9i SQL Reference

TREAT

TREAT

Syntax treat::=

Purpose

TREAT changes the declared type of an expression.

You must have the EXECUTE object privilege on type to use this function.

■If the declared type of expr is source_type, then type must be some supertype or subtype of source_type. If the most specific type of expr is type (or some subtype of type), then TREAT returns expr. If the most specific type of expr is not type (or some subtype of type), then TREAT returns NULL.

■If the declared type of expr is REF source_type, then type must be some subtype or supertype of source_type. If the most specific type of DEREF(expr) is type (or a subtype of type), then TREAT returns expr. If the most specific type of DEREF(expr) is not type (or a subtype of type), then

TREAT returns NULL.

Functions 6-191

TRIM

Note: This function does not support CLOB data directly. However, CLOBs can be passed in as arguments through implicit data conversion. Please refer to "Datatype Comparison Rules" on page 2-45 for more information.

Examples

The following statement uses the table oe.persons, which is created in "Substitutable Table and Column Examples" on page 15-67. That table is based on the person_t type, which is created in "Type Hierarchy Example" on page 16-22. The example retrieves the salary attribute of all people in the persons table, the value being null for instances of people that are not employees.

SELECT name, TREAT(VALUE(p) AS employee_t).salary salary

FROM persons p;

You can use the TREAT function to create an index on the subtype attributes of a substitutable column. For an example, see "Indexing on Substitutable Columns: Examples" on page 13-93.

TRIM

Syntax trim::=

LEADING

trim_character

TRAILING

6-192 Oracle9i SQL Reference

TRIM

Purpose

TRIM enables you to trim leading or trailing characters (or both) from a character string. If trim_character or trim_source is a character literal, then you must enclose it in single quotes.

■If you specify LEADING, then Oracle removes any leading characters equal to trim_character.

■If you specify TRAILING, then Oracle removes any trailing characters equal to trim_character.

■If you specify BOTH or none of the three, then Oracle removes leading and trailing characters equal to trim_character.

■If you do not specify trim_character, then the default value is a blank space.

■If you specify only trim_source, then Oracle removes leading and trailing blank spaces.

■The function returns a value with datatype VARCHAR2. The maximum length of the value is the length of trim_source.

■If either trim_source or trim_character is null, then the TRIM function returns null.

Both trim_character and trim_source can be any of the datatypes CHAR,

VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. The string returned is of

VARCHAR2 datatype and is in the same character set as trim_source.

Examples

This example trims leading and trailing zeroes from a number:

SELECT TRIM (0 FROM 0009872348900) "TRIM Example"

FROM DUAL;

TRIM Example

------------

98723489

Functions 6-193