1/18/2024 0 Comments Decode oracle sqlA user-defined operator (see CREATE OPERATOR and Oracle8i Data Cartridge Developer's Guide ).A function in a user-defined package or in a standalone user-defined function (see "User-Defined Functions" ).A function in an Oracle-supplied package (see Oracle8i Supplied PL/SQL Packages Reference).A SQL built-in function (see Chapter 4, "Functions").See Also: "SQL Functions" and "Aggregate Functions" for information on built-in functionsĪ function expression specifies a call to Some valid built-in function expressions are: :employee_name INDICATOR :employee_name_indicator_varĪ built-in function expression specifies a call to a single-row SQL function. Note that this form of expression can appear only in embedded SQL statements or SQL statements processed in an Oracle Call Interface (OCI) program. For example, the LENGTH function is inappropriate within an aggregate function.Ī variable expression specifies a host variable with an optional indicator variable. Note that some combinations of functions are inappropriate and are rejected. See Also: "Pseudocolumns" for more information on pseudocolumnsĪ compound expression specifies a combination of other expressions. The sections that follow describe and provide examples of the various forms of expressions. You must use appropriate expression notation whenever expr appears in conditions, SQL functions, or SQL statements in other parts of this reference. Oracle does not accept all forms of expressions in all parts of all SQL statements. This SET clause has the expression LOWER( ename) instead of the quoted string ' smith':Įxpressions have several forms, as shown in the following syntax: The VALUES clause of the INSERT statementįor example, you could use an expression in place of the quoted string 'smith' in this UPDATE statement SET clause:.The CONNECT BY, START WITH, and ORDER BY clauses.A condition of the WHERE clause and HAVING clause.The select list of the SELECT statement.The expression adds seven days to the current date, removes the time component from the sum, and converts the result to CHAR datatype: The following expression is an example of a more complex expression that uses both functions and operators. This simple expression evaluates to 4 and has datatype NUMBER (the same datatype as its components): An expression generally assumes the datatype of its components. This chapter describes how to combine the values, operators, and functions described in earlier chapters evaluate to a value.Īn expression is a combination of one or more values, operators, and SQL functions that evaluate to a value.
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