Managing Your Database › Data Extraction › Data Selection for Extraction

Data Selection for Extraction

To select the data for extraction, the data extractor uses an integral SQL subset with the following rules:

• The following SQL functions are specifically supported in the subset:
  • IS NULL, IS NOT NULL, LIKE
  • SELECT statements and WHERE clauses
• The following SQL functionality is not supported in the subset:
  • Joins
  • Embedded tabs and new‑line characters
  • Clauses other than SELECT, FROM, and WHERE
  • Asterisks ( * ) in SELECT statements
  • Nested SELECTs
  • Aggregate functions
• All SQL reserved words must be in uppercase characters
• Every token in a WHERE clause must be surrounded by white space
• All date/time specifications must be in one of three formats:
  • Elapsed seconds from 12:00:00 a.m. 1/1/1970 Greenwich Mean Time (GMT):

    start_date< or >174182431500
    

  • SQL DATE format:

    start_date< or >DATE '2001‑11‑28'
    

  • SQL TIMESTAMP format:

    start_date< or >TIMESTAMP '2001‑07‑04 15:45:00'
    

Note: TIMESTAMP format uses GMT. You can adjust time zones by adding or subtracting the appropriate number of hours, such as: 2001‑03‑23 14:00:00+02:00 or 2001‑06‑06 04:45:00‑09:00.