EQ or = operator

Returns a TRUE value if two expressions are equal.

Syntax 

 

expression { EQ | = } expression

expression

A constant, field name, variable name, or expression. The expressions on either side of the EQ or = must be of the same data type, although one might be an integer and the other a decimal.

Example 

This procedure prompts for the initials of a sales rep. The FOR EACH block reads all the order records for that sales rep. The DISPLAY statement displays information from each of the retrieved records.

 

r-eq.p

PROMPT-FOR Order.SalesRep WITH SIDE-LABELS CENTERED.   FOR EACH Order NO-LOCK WHERE Order.SalesRep EQ INPUT Order.SalesRep: DISPLAY Order.OrderNum Order.CustNum Order.OrderDate Order.PromiseDate     Order.ShipDate WITH CENTERED. END.

Notes 

By default, the AVM uses the collation rules you specify to compare characters and sort records. The collation rules specified with the Collation Table (-cpcoll) startup parameter take precedence over a collation specified for any database the AVM accesses during the session, except when the AVM uses or modifies pre-existing indexes. If you do not specify a collation with the -cpcoll startup parameter, the AVM uses the language collation rules defined for the first database on the command line. If you do not specify a database on the command line, the AVM uses the collation rules with the default name "basic" (which might or might not exist in the convmap.cp file).

You can compare character strings with EQ. Most character comparisons are case insensitive in ABL. That is, upper-case and lower-case characters have the same sort value. However, it is possible to define fields and variables as case sensitive (although it is not advised, unless strict ANSI SQL adherence is required). If either expression is a field or variable defined as case sensitive, the comparison is case sensitive and “Smith” does not equal “smith”.

Characters are converted to their sort code values for comparison. Using the default case-sensitive collation table, all uppercase letters sort before all lowercase letters (for example, a is greater than Z, but less than b.) Note also that in character code uppercase A is less than [ , \ , ^ , _, and  ’ , but lowercase a is greater than these.

If one of the expressions has an Unknown value (?) and the other does not, the result is FALSE. If both have the Unknown value (?), the result is TRUE. However, for SQL, if the value of either or both expressions is the Unknown value (?), then the result is the Unknown value (?).

The equal comparison ignores trailing blanks. Thus, “abc” is equal to “abc “. However, leading and embedded blanks are treated as characters and “ abc” is not equal to “abc”.

You cannot compare data of different DATE, DATETIME, and DATETIME-TZ data types to each other using EQ. You must first convert different date and datetime data types to the same data type before doing a comparison between them.

You can use EQ to compare one BLOB field to another. The AVM performs a byte-by-byte comparison.

You can use EQ to compare a LONGCHAR variable to another LONGCHAR or CHARACTER variable. The variable values are converted to -cpinternal for comparison and must convert without error, or the AVM raises a run-time error.

You can use EQ to compare a CLOB field to another CLOB field.