Transformation Language Reference > Functions > INSTR

INSTR

Returns the position of a character set in a string, counting from left to right.

Syntax

INSTR( string, search_value [,start [,occurrence [,comparison_type ]]] )

The following table describes the arguments for this command:

Argument	Required/ Optional	Description
string	Required	The string must be a character string. Passes the value you want to evaluate. You can enter any valid transformation expression. The results of the expression must be a character string. If not, INSTR converts the value to a string before evaluating it.
search_value	Required	Any value. The search value is case sensitive. The set of characters you want to search for. The search_value must match a part of the string. For example, if you write INSTR('Alfred Pope', 'Alfred Smith') the function returns 0. You can enter any valid transformation expression. If you want to search for a character string, enclose the characters you want to search for in single quotation marks, for example 'abc'.
start	Optional	Must be an integer value. The position in the string where you want to start the search. You can enter any valid transformation expression. The default is 1, meaning that INSTR starts the search at the first character in the string. If the start position is 0, INSTR searches from the first character in the string. If the start position is a positive number, INSTR locates the start position by counting from the beginning of the string. If the start position is a negative number, INSTR locates the start position by counting from the end of the string. If you omit this argument, the function uses the default value of 1.
occurrence	Optional	A positive integer greater than 0. You can enter any valid transformation expression. If the search value appears more than once in the string, you can specify which occurrence you want to search for. For example, you would enter 2 to search for the second occurrence from the start position. If you omit this argument, the function uses the default value of 1, meaning that INSTR searches for the first occurrence of the search value. If you pass a decimal, the Data Integration Service rounds it to the nearest integer value. If you pass a negative integer or 0, the session fails.
comparison_type	Optional	The string comparison type, either linguistic or binary, when the Data Integration Service runs in Unicode mode. When the Data Integration Service runs in ASCII mode, the comparison type is always binary. Linguistic comparisons take language-specific collation rules into account, while binary comparisons perform bitwise matching. For example, the German sharp s character matches the string “ss” in a linguistic comparison, but not in a binary comparison. Binary comparisons run faster than linguistic comparisons. Must be an integer value, either 0 or 1: - 0: INSTR performs a linguistic string comparison. - 1: INSTR performs a binary string comparison. Default is 0. If you enter 0, the session sort order must not be binary.

Return Value

Integer if the search is successful. Integer represents the position of the first character in the search_value, counting from left to right.

0 if the search is unsuccessful.

NULL if a value passed to the function is NULL.

Examples

The following expression returns the position of the first occurrence of the letter ‘a’, starting at the beginning of each company name. Because the search_value argument is case sensitive, it skips the ‘A’ in ‘Blue Fin Aqua Center’, and returns the position for the ‘a’ in ‘Aqua’:

INSTR( COMPANY, 'a' )

COMPANY	RETURN VALUE
Blue Fin Aqua Center	13
Maco Shark Shop	2
Scuba Gear	5
Frank's Dive Shop	3
VIP Diving Club	0

The following expression returns the position of the second occurrence of the letter ‘a’, starting at the beginning of each company name. Because the search_value argument is case sensitive, it skips the ‘A’ in ‘Blue Fin Aqua Center’, and returns 0:

INSTR( COMPANY, 'a', 1, 2 )

COMPANY	RETURN VALUE
Blue Fin Aqua Center	0
Maco Shark Shop	8
Scuba Gear	9
Frank's Dive Shop	0
VIP Diving Club	0

The following expression returns the position of the second occurrence of the letter ‘a’ in each company name, starting from the last character in the company name. Because the search_value argument is case sensitive, it skips the ‘A’ in 'Blue Fin Aqua Center’, and returns 0:

INSTR( COMPANY, 'a', -1, 2 )

COMPANY	RETURN VALUE
Blue Fin Aqua Center	0
Maco Shark Shop	2
Scuba Gear	5
Frank's Dive Shop	0
VIP Diving Club	0

The following expression returns the position of the first character in the string ‘Blue Fin Aqua Center’ (starting from the last character in the company name):

INSTR( COMPANY, 'Blue Fin Aqua Center', -1, 1 )

COMPANY	RETURN VALUE
Blue Fin Aqua Center	1
Maco Shark Shop	0
Scuba Gear	0
Frank's Dive Shop	0
VIP Diving Club	0

Using Nested INSTR

You can nest the INSTR function within other functions to accomplish more complex tasks.

The following expression evaluates a string, starting from the end of the string. The expression finds the last (rightmost) space in the string and then returns all characters to the left of it:

SUBSTR( CUST_NAME,1,INSTR( CUST_NAME,' ' ,-1,1 ))

CUST_NAME	RETURN VALUE
PATRICIA JONES	PATRICIA
MARY ELLEN SHAH	MARY ELLEN

The following expression removes the character '#' from a string:

SUBSTR( CUST_ID, 1, INSTR(CUST_ID, '#')-1 ) || SUBSTR( CUST_ID, INSTR(CUST_ID, '#')+1 )

CUST_ID	RETURN VALUE
ID#33	ID33
#A3577	A3577
SS #712403399	SS 712403399