 We studied the problem of using SQL to support search-as-you-type in data bases.  We focused on the challenge of how to leverage existing DBMS functionalities to meet the high-performance requirement to achieve an interactive speed.  To support prefix matching, we proposed solutions that use auxiliary tables as index structures and SQL queries to support search-as-you-type.  We extended the techniques to the case of fuzzy queries, and proposed various techniques to improve query performance.  We proposed incremental-computation techniques to answer multi key word queries, and studied how to support first-N queries and incremental updates.  Our experimental results on large, real data sets showed that the proposed techniques can enable DBMS systems to support search-as-you-type on large tables.