What are cross apply and outer apply in SQL Server?

Asked By: Samou Miguez | Last Updated: 16th March, 2020
Category: technology and computing databases
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SQL Server APPLY operator has two variants; CROSS APPLY and OUTER APPLY. The CROSS APPLY operator returns only those rows from the left table expression (in its final output) if it matches with the right table expression. In other words, the right table expression returns rows for the left table expression match only.

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Likewise, people ask, what is cross apply and outer apply in SQL Server?

SQL Server APPLY operator has two variants; CROSS APPLY and OUTER APPLY. The CROSS APPLY operator returns only those rows from the left table expression (in its final output) if it matches with the right table expression. In other words, the right table expression returns rows for the left table expression match only.

Secondly, when we use cross apply in SQL Server? CROSS APPLY returns only rows from the outer table that produce a result set from the table-valued function. It other words, result of CROSS APPLY doesn't contain any row of left side table expression for which no result is obtained from right side table expression. CROSS APPLY work as a row by row INNER JOIN.

Furthermore, when to use Cross Apply and Outer Apply?

It retrieves those records from the table valued function and the table being joined, where it finds matching rows between the two. On the other hand, OUTER APPLY retrieves all the records from both the table valued function and the table, irrespective of the match.

Why we use cross join?

A cross join is used when you wish to create combination of every row from two tables. All row combinations are included in the result; this is commonly called cross product join. A common use for a cross join is to create obtain all combinations of items, such as colors and sizes.

21 Related Question Answers Found

What is difference between cross join and cross join?

1. A cross join that does not have a WHERE clause produces the Cartesian product of the tables involved in the join. 1. The APPLY operator allows you to invoke a table-valued function for each row returned by an outer table expression of a query.

What is coalesce in SQL?

What is COALESCE? COALESCE is a built-in SQLServer Function. Use COALESCE when you need to replace a NULL with another value. It takes the form: COALESCE(value1, value2, , valuen) It returns the first non NULL from the value list.

Is Cross join same as outer join?

10 Answers. A cross join produces a cartesian product between the two tables, returning all possible combinations of all rows. A full outer join is a combination of a left outer and right outer join.

What is the difference between left join and left outer join?

In SQL, the left join returns all the records from first table and matched records from second table. If there is no match from second table then only records from first table are returned. Basically there is no difference in left join and left outer join. Left outer join also returns same results as left join.

How does cross join work in SQL?


In SQL, the CROSS JOIN is used to combine each row of the first table with each row of the second table. It is also known as the Cartesian join since it returns the Cartesian product of the sets of rows from the joined tables.

What is a table valued expression?

A table-valued function is a user-defined function that returns data of a table type. The return type of a table-valued function is a table, therefore, you can use the table-valued function just like you would use a table.

What is difference between inner join and outer join in SQL?

Both inner and outer joins are used to combine rows from two or more tables into a single result. This is done using a join condition. The join condition specifies how columns from each table are matched to one another. Inner joins don't include non-matching rows; whereas, outer joins do include them.

What does inner join mean in SQL?

What is Inner Join in SQL? The INNER JOIN selects all rows from both participating tables as long as there is a match between the columns. An SQL INNER JOIN is same as JOIN clause, combining rows from two or more tables. Here is an example of inner join in SQL between two tables.

How do you pivot in SQL?

SQL Server PIVOT operator rotates a table-valued expression.

You follow these steps to make a query a pivot table:
  1. First, select a base dataset for pivoting.
  2. Second, create a temporary result by using a derived table or common table expression (CTE)
  3. Third, apply the PIVOT operator.

How do I find the execution plan in SQL Server?


Use SQL Server Profiler
  1. Start SQL Server Profiler.
  2. In the File menu, select New Trace.
  3. In the Events Section tab, check Show all events.
  4. Expand the Performance node.
  5. Select Showplan XML.
  6. Execute the query you want to see the query plan for.
  7. Stop the trace.
  8. Select the query plan in the grid.

What is cross apply in Oracle?

The CROSS APPLY join is a variant of the ANSI CROSS JOIN . It returns all rows from the left hand table, where at least one row is returned by the table reference or collection expression on the right. The right side of the APPLY can reference columns in the FROM clause to the left.

What is cross apply in MySQL?

Cross Join. In MySQL, the CROSS JOIN produced a result set which is the product of rows of two associated tables when no WHERE clause is used with CROSS JOIN. In MySQL, the CROSS JOIN behaves like JOIN and INNER JOIN of without using any condition.

How apply join in SQL?

Different types of JOINs
  1. (INNER) JOIN: Select records that have matching values in both tables.
  2. LEFT (OUTER) JOIN: Select records from the first (left-most) table with matching right table records.
  3. RIGHT (OUTER) JOIN: Select records from the second (right-most) table with matching left table records.

What is CTE in SQL Server 2008 with example?

CTE was introduced in SQL Server 2005, the common table expression (CTE) is a temporary named result set that you can reference within a SELECT, INSERT, UPDATE, or DELETE statement. In addition, as of SQL Server 2008, you can add a CTE to the new MERGE statement.

Can you create a function and have dynamic SQL in it?


3 Answers. You can't call stored procedures from within a function, including the stored procedures EXECUTE or SP_EXECUTESQL . This means that you can't have dynamic sql embedded within a function.

How use outer join in SQL?

SQL left outer join is also known as SQL left join. Suppose, we want to join two tables: A and B. SQL left outer join returns all rows in the left table (A) and all the matching rows found in the right table (B). It means the result of the SQL left join always contains the rows in the left table.