Specifying the Data Field Delimiter

Query Reference Manual

Communicating Using Query : Specifying the Data Field Delimiter

When data is sent from a data server to Query, it is sent as a single data block. Each data field within the block is delimited by a special character; by default, this is the ~ (tilde) character. When Query receives the block, it uses the delimiter character to determine the points at which to split the data into individual fields. If the data includes the delimiter character within a text field, Query will split the data block at the wrong point.

For example, the data stored in the following fields:


Area	Catalytic Cracker
Plant	Reflux~Heater
Code	DES21142

would be received by Query, using the default ~ delimiter, as the data block

Catalytic Cracker~Reflux~Heater~DES21142

and would be split, incorrectly, into the fields


$!a[1]	Catalytic Cracker
$!a[2]	Reflux
$!a[3]	Heater
$!a[4]	DES21142

To prevent this effect, you can redefine the delimiter character to be any single character which is not used within any database field. To do so, use the command


EXTERnal DELImit token text_char

where token is the token for the communication channel which was supplied by a successful EXTERNAL OPEN command (and stored in the token_var variable) and text_char is the required data field delimiter character.

For example, the specification

EXTERNAL DELIMIT $!!MAINT ’&’

would cause the data block from the preceding example to be received as

Catalytic Cracker&Reflux~Heater&DES21142

which would be correctly split at the points identified by the & characters.