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Download Informix Guide to SQL: Syntax, Version 6.0
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Expression Use a table or alias name whenever it is necessary to distinguish between columns that have the same name but are in different tables. The SELECT statements shown in the following example use customer_num from the customer and orders tables, so they precede the column names with the table names: SELECT * FROM customer, orders WHERE customer.customer_num = orders.customer_num SELECT * FROM customer c, orders o WHERE c.customer_num = o.customer_num Using Subscripts on Character Columns You can use subscripts on CHAR, VARCHAR, NCHAR, NVARCHAR, BYTE, and TEXT columns. The subscripts indicate the starting and ending character positions contained in the expression. For example, if a value in the lname column of the customer table is Greenburg, the following expression evaluates to burg: fname[6,9] 1-434 Syntax
