The MINUS operator in Oracle is used to return unique rows from the left query which isn’t present in the right query’s results. That means the MINUS Operator takes the result set of the first select statement and removes those rows that are returned by a second select statement.
Full Answer
What does MINUS do in Oracle SQL?
The Oracle MINUS operator is used to return all rows in the first SELECT statement that are not returned by the second SELECT statement. Each SELECT statement will define a dataset. The MINUS operator will retrieve all records from the first dataset and then remove from the results all records from the second dataset.
Does Oracle support MINUS?
You can combine multiple queries using the set operators UNION , UNION ALL , INTERSECT , and MINUS . All set operators have equal precedence. If a SQL statement contains multiple set operators, then Oracle Database evaluates them from the left to right unless parentheses explicitly specify another order.
How does MINUS query work?
What is a Minus Query? A Minus Query is a query that uses the MINUS operator in SQL to subtract one result set from another result set to evaluate the result set difference. If there is no difference, there is no remaining result set. If there is a difference, the resulting rows will be displayed.
How does MINUS operator work in SQL?
The Minus Operator in SQL is used with two SELECT statements. The MINUS operator is used to subtract the result set obtained by first SELECT query from the result set obtained by second SELECT query.
What is the use of MINUS?
The minus sign is used to represent negative integers, whole numbers less than zero (no fractions). For representing a negative integer, add a negative sign in front of a whole number. Multiplication of two negative numbers gives a positive. For example, A temperature of – 3˚ C means 3 degrees below zero.
What is the difference between MINUS and not exists in Oracle?
If both tables a roughly the same size, then MINUS might be faster, particularly if you can live with only seeing fields that you are comparing on. If you wanted to see if you had retirees that were not in the employee table, then you could use either MINUS or NOT EXISTS (or even NOT IN, but you didn't ask).
Will MINUS remove duplicates?
What is true about the MINUS operator? Answer: A. MINUS Returns only the rows in the first result set that do not appear in the second result set, sorting them and removing duplicates.
Is MINUS and except same in SQL?
There is absolutely no difference in the EXCEPT clause and the MINUS clause. They both serve the same purpose and they are simply two different ways of achieving the same functionality. The difference is that EXCEPT is available in the PostgreSQL database while MINUS is available in MySQL and Oracle.
How do you write a MINUS statement in SQL?
To use the MINUS operator, you write individual SELECT statements and place the MINUS operator between them. The MINUS operator returns the unique rows produced by the first query but not by the second one.
Can I MINUS date in SQL?
Discussion: If you would like to subtract dates or times in SQL Server, use the DATEADD() function.
Can you subtract two columns in SQL?
You subtract both columns and display it as column like below query. SELECT col1,col2,(col1-col2) as col3 FROM table; This will display the difference in third column.
How do I subtract two time columns in SQL?
MySQL SUBTIME() Function The SUBTIME() function subtracts time from a time/datetime expression and then returns the new time/datetime.
Can we use MINUS in SQL Server?
TIP: The MINUS operator is not supported in all SQL databases. It can used in databases such as Oracle. For databases such as SQL Server, PostgreSQL, and SQLite, use the EXCEPT operator to perform this type of query.
What is the alternative for MINUS in SQL?
EXCEPT clauseAbsolutely, EXCEPT clause in SQL Server is exactly similar to MINUS operation in Oracle. The EXCEPT query and MINUS query returns all rows in the first query that are not returned in the second query.
Is MINUS supported in hive?
Apache Hive does not support MINUS set operator. If you have any requirement to perform MINUS, then you have to rewrite your queries using an alternate method. There are two methods that you can use: Use LEFT OUTER JOIN.
Is MINUS the same as except in SQL?
There is absolutely no difference in the EXCEPT clause and the MINUS clause. They both serve the same purpose and they are simply two different ways of achieving the same functionality. The difference is that EXCEPT is available in the PostgreSQL database while MINUS is available in MySQL and Oracle.
What is a minus in Oracle?
MINUS operator in Oracle is used in between multiple select statements, in turn to fetch the unique records out of all the select queries. The resulting outputs are the rows that does not repeat for more than one select statement in the MINUS query that was executed. The select queries here are executed separately, while the results are combined, and MINUS is applied on this result to get the final output. It is one of the VERTICAL JOIN operators available in Oracle’s PL/SQL.
What is the result of each select statement?
The result of each SELECT statement can be treated as a set and MINUS operator applies on the sets and combines the result sets to get the one final result or a single set with the record (s) that exists only in FIRST SELECT statement and that would be UNIQUE.
Why does the MINUS operator return zero?
In this example, MINUS operator returns ZERO record because each SELECT statement generates an individual set of the result but during the merge of the result sets, all records of the first result set exist in the second result set.
How many columns are in a second select statement?
But in this example, the first SELECT statement contains three columns but the second SELECT statement contains two columns.
What does a minus query return?
Explanation: The MINUS query returns the record in the red outline area but does not share with the black outline area i.e. 1. This is the record that exists in Dataset 1 but not in Dataset 2.
Does a select statement contain an order by clause?
To sort the final result set, a SELECT statement may contain an ORDER BY clause but the last SELECT statement only may contain the ORDER BY clause.
Can column position number be used instead of column name?
In the ORDER BY clause, column position number can be also used instead of a column name.
An Alternative
It’s possible to get the same result without using the MINUS operator. For example, we could rewrite our first example to this:
MINUS Equivalents in Other RDBMSs
Oracle’s MINUS operator is similar to the EXCEPT operator that many other RDBMS s use. MariaDB has an EXCEPT operator, but it has also introduced a MINUS operator as a synonym that can be used when in Oracle mode.
How often is a rowset scanned?
The advantage - especially if the rowsets are base tables - is that each is only scanned once, instead of twice each.
What does max(bar) tell you?
This gives you all foo that have only either bar 1 or bar 2 and not both. And max(bar)tells you which of the two values a foo has.
What is the meaning of "back up"?
Making statements based on opinion; back them up with references or personal experience.
Can you use intersect but the number of select are pratically the same?
you could use intersect but the number of select are pratically the same
Can you use two rowsets in a deduplicated table?
If the two rowsets (be they base tables or the results of other computations) are already de-duplicated, then you can use
Does UNION ALL remove duplicates?
Set operations (UNION, INTERSECT, MINUS) remove duplicates. Only UNION ALL preserves all duplicates. So - first question - are the two rowsets for which you want to compute the symmetric difference de-duplicated already? ("Symmetric difference" is the technical term for the set operation you are asking about; the set-theoretic equivalent of "exclusive OR".) If they are de-duplicated already, then yes, there are more efficient ways, but first please clarify this.
How many rows does minus return?
Wrong. If there are no duplicates then MINUS would return 425 rows.
What happens if there are two identical rows in table_A?
If there are two identical rows in table_A, and that same row exists in table_B, BOTH rows from table_A will be removed from the result set.
Points of Concentration
Examples to Implement Minus in Oracle
- In this section, we’ll see the implementation of the MINUS operator and its behavior. For that, we will use the below sample table (Emp) with 14 records to understand the MINUS operator behavior. Query: SELECT * from Emp; Output:
Rules and Restrictions
- Following are the important rules and restrictions of MINUS operator as listed below: 1. The result sets of the queries must have the same number of columns. 2. The data type of each column in the second result set must match the data type of its corresponding column in the first result set. 3. The two SELECT statements may not contain an ORDER BY clause, but the final result of the …
Conclusion
- MINUS Operator performs VERTICAL Join and returns only those record(s) that is/are NOT existing in second result set. To get the record(s), that is/are UNIQUE and doesn’t exist in the second SELECT statement result set, MINUS operator can be used but column(s) number and data type must be the same.
Recommended Articles
- This is a guide to MINUS in Oracle. Here we discuss what is MINUS operator in oracle and points of concentration including rules and restriction with its examples. You may also look at the following articles to learn more – 1. Examples of SQL SELECT Query 2. How to Fetch the Data From Database? 3. Architecture of Oracle Database 4. Steps to Install Oracle