71 lines
1.8 KiB
Plaintext
71 lines
1.8 KiB
Plaintext
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Functions with <code>OUT</code> parameters are complex to understand. Indeed, it is impossible to tell, just by looking at the function call, whether an argument is a input or output. Moreover, functions with <code>OUT</code> parameters cannot be called from SQL. It is better to either break such functions up into smaller ones, which each return a single value, or to return several values at once, by combining them in a collection, record, type, or table row.
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== Noncompliant Code Example
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----
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SET SERVEROUTPUT ON
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CREATE TABLE employee(
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firstName VARCHAR2(42),
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name VARCHAR2(42),
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phone VARCHAR2(42)
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);
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INSERT INTO employee VALUES ('John', 'Smith', '+1');
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DECLARE
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firstName VARCHAR2(42);
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name VARCHAR2(42);
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phone VARCHAR2(42);
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-- This DOES NOT return the employee name
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FUNCTION getEmployeeInfos(firstName OUT VARCHAR2, phone OUT VARCHAR2) RETURN VARCHAR2 AS -- Non-Compliant, confusing
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name VARCHAR2(42);
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BEGIN
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SELECT firstName, name, phone INTO firstName, name, phone FROM employee;
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RETURN name;
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END;
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BEGIN
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name := getEmployeeInfos(firstName, phone);
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DBMS_OUTPUT.PUT_LINE('firstName: ' || firstName);
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DBMS_OUTPUT.PUT_LINE('name: ' || name);
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DBMS_OUTPUT.PUT_LINE('phone: ' || phone);
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END;
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/
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----
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== Compliant Solution
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----
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SET SERVEROUTPUT ON
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CREATE TABLE employee(
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firstName VARCHAR2(42),
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name VARCHAR2(42),
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phone VARCHAR2(42)
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);
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INSERT INTO employee VALUES ('John', 'Smith', '+1');
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DECLARE
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emp employee%ROWTYPE;
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FUNCTION getEmployeeInfos RETURN employee%ROWTYPE AS -- Compliant
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emp employee%ROWTYPE;
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BEGIN
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SELECT * INTO emp FROM employee;
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RETURN emp;
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END;
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BEGIN
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emp := getEmployeeInfos;
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DBMS_OUTPUT.PUT_LINE('firstName: ' || emp.firstName);
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DBMS_OUTPUT.PUT_LINE('name: ' || emp.name);
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DBMS_OUTPUT.PUT_LINE('phone: ' || emp.phone);
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END;
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/
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DROP TABLE employee;
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----
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