text and image Datatypes

The text datatype is used to store printable character data, the column size of which depends on the logical page size of the SAP ASE.

The image datatype is used to store a number of bytes of hexadecimal-encoded binary data that, again, depends on the logical page size of the SAP ASE. The maximum length for text, image, and unitext data is defined by the server class of the remote server to which the column is mapped.

Processing text, unitext, and image data (with remote servers only) can be logged by using trace flag 11207.

• Limits of @@textsize
  select statements return text, image, and unitext data up to the limit specified in the global variable @@textsize.
• Odd Bytes Padded
  image values of less than 255 bytes that have an odd number of bytes are padded with a leading zero (an insert of “0xaaabb” becomes “0x0aaabb”).
• Converting text and image Datatypes
  You can explicitly convert text values to char or varchar and image values to binary or varbinary with the convert function.
• Pattern Matching with text and unitext Data
  Use the patindex function to search for the starting position of the first occurrence of a specified pattern in a text, unitext, varchar, or char column.
• Entering text and image Values
  The DB-Library™ functions dbwritetext and dbmoretext and the Client-Library function ct_send_data are the most efficient ways to enter text, unitext, and image values.
• readtext using bytes
  Errors result if you use the readtext using bytes command on a text column, and the combination of size and offset result in the transmission of a partial character.
• Restriction for text, image, and unitext with bulk copy
  FIXME: Short description?
• Considerations for Using text, unitext, and image data with Server Classes
  The ASEnterprise server class includes some restrictions for text, unitext, or image data.