How do I MERGE two rows in SQL Server?

You can concatenate rows into single string using COALESCE method. This COALESCE method can be used in SQL Server version 2008 and higher. All you have to do is, declare a varchar variable and inside the coalesce, concat the variable with comma and the column, then assign the COALESCE to the variable.

What is purpose of MERGE in SQL Server 2008?

In SQL Server 2008, you can perform insert, update, or delete operations in a single statement using the MERGE statement. The MERGE statement allows you to join a data source with a target table or view, and then perform multiple actions against the target based on the results of that join.

What can I use instead of MERGE in SQL?

The alternative way, which you can use instead of applying the MERGE statement, is to write a sequence of INSERT, UPDATE, and DELETE statements, where, for each row, the decision is made whether to insert, delete, or update the data.

What is MERGE command in SQL Server?

The MERGE statement in SQL is a very popular clause that can handle inserts, updates, and deletes all in a single transaction without having to write separate logic for each of these. The MERGE statement tries to compare the source table with the target table based on a key field and then do some of the processing.

Is MERGE faster than insert update?

The basic set-up data is as follows. We’ve purposely set up our source table so that the INSERTs it will do when merged with the target are interleaved with existing records for the first 500,000 rows. These indicate that MERGE took about 28% more CPU and 29% more elapsed time than the equivalent INSERT/UPDATE.

What is MERGE in SQL Server with example?

Runs insert, update, or delete operations on a target table from the results of a join with a source table. For example, synchronize two tables by inserting, updating, or deleting rows in one table based on differences found in the other table. MERGE is currently in preview for Azure Synapse Analytics.

What is merge join in SQL?

Merge join is used when projections of the joined tables are sorted on the join columns. In this case, the optimizer builds an in-memory hash table on the inner table’s join column. The optimizer then scans the outer table for matches to the hash table, and joins data from the two tables accordingly.

How do I MERGE 3 tables in SQL?

How to join 3 or more tables in SQL

1. Simple Join. First, all the tables are joined using the JOIN keyword, then the WHERE clause is used: FROM Employee e JOIN Salary s JOIN Department d. WHERE e. ID = s. Emp_ID AND e.
2. Nested Join. The nested JOIN statement is used with the ON keyword: SELECT e. ID, e. Name, s. Salary, d.

How do I have multiple rows in one row in SQL?

STUFF Function in SQL Server

1. Create a database.
2. Create 2 tables as in the following.
3. Execute this SQL Query to get the student courseIds separated by a comma. USE StudentCourseDB. SELECT StudentID, CourseIDs=STUFF. ( ( SELECT DISTINCT ‘, ‘ + CAST(CourseID AS VARCHAR(MAX)) FROM StudentCourses t2.

Can you merge cells and keep all data?

If you merge multiple columns of data in Excel (no matter which Excel version you are using), only the left column of data will be kept, and the data of other columns will be deleted, if you apply the “Merge and Center” command from Home tab on the Alignment group.

How do I insert multiple rows in SQL?

Method 1. Pick where you want to insert the multiple rows. Then hold CTRL+SHIFT and press the + key. This will result in a single blank row being inserted below it. Now you can keep pressing the + symbol or hold it down and it will keep inserting blank rows. The below picture is after pressing the + key 5 times.

How many rows can I import from Excel to SQL?

For SQL, this number is four. During a lifetime you should import exactly four rows from excel into SQL. If you insert less than four, you have really not succeeded in life. If you’ve inserted more, well, then you’ve stolen other people’s row imports.

How to delete multiple rows from two tables in SQL?

MySQL also allows you to use the INNER JOIN clause in the DELETE statement to delete rows from a table and the matching rows in another table. For example, to delete rows from both T1 and T2 tables that meet a specified condition, you use the following statement: DELETE T1, T2 FROM T1 INNER JOIN T2 ON T1.key = T2.key WHERE condition;

What is select top 1 in SQL?

Diff between Top 1 1 and Select 1 in SQL Select Query. In the following, the first “1”, which is part of the “TOP 1” means to stop after it gets to a single result. The second “1” is just because the author really does not care what the result is.