Joe Celko was a member of the ANSI X3H2 Database Standards Committee from
1987 to 1997 and helped write the ANSI/ISO SQL-89 and SQL-92 standards. He has written over 750 columns in the computer trade and academic press,
mostly dealing with data and databases. His current magazine column is
"CELKO" in INTELLIGENT ENTERPRISE magazine (CMP).
He is the author of five books: SQL FOR SMARTIES (Morgan-Kaufmann, 1995,
second edition 1999), SQL PUZZLES & ANSWERS (Morgan-Kaufmann, 1997), DATA &
DATABASES (Morgan-Kaufmann, 1999) and TREES & HIERARCHIES IN SQL