1.1.2 Basic rules for writing a SELECT statement

The basic rules for writing a SELECT statement are as follows:

• We recommend that table names and column names specified in the SELECT statement be enclosed in double quotation marks ("). Enclosing a table or column name in double quotation marks allows you to specify the same name as an SQL reserved word, and eliminates the need to rewrite the SQL statement if a reserved word with that same name is added in the future.

  In addition, if a name is not enclosed in double quotation marks, any lowercase letters are treated as uppercase. For example, if you specify name, it is treated as NAME.

• Enclose CHAR type and VARCHAR type character string data in single quotation marks (').

  Example: WHERE "NAME"='Taro Tanaka'

• For type DATE data, enter dates in the following manner.

  Example 1: WHERE "PUR-DATE">=DATE'2011-09-06'

  Example 2: WHERE "PUR-DATE">=DATE'2011/09/06'

  The date format in Example 1 is used in the examples of SELECT statements given in this chapter.

• INTEGER type numeric data is not enclosed in single quotation marks (').

  Example: WHERE "PUR-NUM"=10

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