Oracle where clause multiple conditions

This Oracle WHERE clause example uses the WHERE clause to define multiple conditions, but it combines the AND condition and the OR condition. Multiple columns in Oracle Where clause. Select with multiple conditions in where clause.

If the problem involves run-time parameters (like p30_category in this example), then give a couple of different sets of parameters, and the you want from each set. Simplify the problem as much as possible.

The WHERE clause appears after the FROM clause but before the ORDER BY clause. Following the WHERE keyword is the search_condition that defines a condition which returned rows must satisfy. Besides the SELECT statement, you can use the WHERE clause in the DELETE or UPDATE statement to specify which rows to update or delete. I have a scenario where I have to run a report in automatic and manual mode.

I want to use the CASE construct after a WHERE clause to build an expression. However, you can specify LEVEL in a subquery of the FROM clause to achieve the same result. SQL is a language to work on sets, so think of your data in database as elements in sets, and your WHERE clause is a way to extract those elements of interest using set expression.

Table 7-lists the levels of precedence among SQL condition from high to low. Oracle evaluates conditions with equal precedence from left to right within an expression. Oracle CASE expression allows you to add if-else logic to SQL statements without having to call a procedure.

The CASE expression evaluates a list of conditions and returns one of the multiple possible. You can use a CASE expression in any statement or clause that accepts a valid expression. If your WHERE clause consists of multiple conditions , the conditions are separated by the logical operators AND and OR.

Depending on the outcome of the individual conditions and the placement of these logical operators, Oracle will assign a final value of TRUE or FALSE to each candidate row, thereby determining whether a row will be included in the final result set. Just code a nested IF statement to handle the multiple conditions - it will be MUCH easier to: code, test, debug and maintain by less experienced developers. The SQL AND condition and OR condition can be combined to test for multiple conditions in a SELECT, INSERT, UPDATE, or DELETE statement. When combining these conditions , it is important to use parentheses so that the database knows what order to evaluate each condition.

SQL multiple columns in IN clause. Oracle ignores rows where one or more of the selected columns is NULL. All Boolean conditions without built-in functions or subqueries are evaluated in reverse from the order they are found in the WHERE clause , with the last predicate being evaluated first. Boolean predicates with built-in functions of each predicate are evaluated in increasing order of their estimated evaluation costs.

I have conditions in where condition in Update clause.

How can I select records from a table , say emp, when I have a parameter for where condition like if empno is known then use in where clause , if ename is known then use ename in where clause , if both are known then use both parameters in where clause. Combining and Negating Conditions with AN OR, and NOT You can specify multiple conditions in a single WHERE clause to, say, retrieve rows based on the values in multiple columns. You can use the AND and OR operators to combine two or more conditions into a compound condition. The Oracle WHERE Clause is used to restrict the rows returned from a query. While the previous chapter ( Basic SELECT Statements ) explained how to extract the names of all customers from Customers table, using the Oracle WHERE clause , you are able to restrict the query to rows that meet a certain condition.

Example 6: WHERE Clause with IN. The SQL WHERE clause can be used with multiple criteria as we’ve just seen. The value for the parameter should be specified as a string with a WHERE clause.

Even in Oracle (and in fact in the SQL standard), CASE is an expression that returns a single value. Each condition joined by AND must evaluate to TRUE for the result to be TRUE. Using IN to match against multiple possibilities.

The IN keyword can be seen as a way to clean up multiple OR conditions.