April 21, 1997

Updating Many Columns

Question: I’m looking for a syntax that can be used to update several columns in an SQLtable. Although I’ve found a number of topics related to ‘update’, they allseem to use the ‘set’ statement for one or two fields only. Answer: The standard UPDATE syntax for updating many columns is

What is normalization?

Question: Will you please help me in locating a definition of the term “normalizeddatabase”? Answer: Normalization of relational databases is the process of ensuring that thedatabase does not contain redundant information. A simple example is thecase of a customer, whose name and address should appear in only one tablebecause its

Length of Table and Column Descriptors

Question: What is the length of a table name or a column name?I know that for some engines it is 18 characters.Is this a SQL limitation or engine limitation ? Answer: This is a limitation of the database server. There is no limitationspecified by the SQL-92 standard.

WHERE (multiple values)

Question: I have a form in which the user can select multiple values of “Manufacturer” from a drop-down list. The query should then select from the database all records in which Manufacturer matches one of those listed. It works fine when a single manufacturer is selected, but what syntax do