A Sql Query Automatically Eliminates Duplicates Code Example

Example 1: sql delete duplicate

-- Oracle DELETE films WHERE rowid NOT IN (     SELECT min(rowid)     FROM films     GROUP BY title, uk_release_date );

Example 2: how to query without duplicate rows in sql

SELECT DISTINCT col1,col2... FROM table_name where Condition;

Example 3: how to remove duplicate in sql

Distinct: helps to remove all the duplicate records when retrieving the records from a table.  SELECT DISTINCT FIRST_NAME FROM VISITORS;

Example 4: sql delete duplicate rows but keep one

# Step 1: Copy distinct values to temporary table CREATE TEMPORARY TABLE tmp_user (     SELECT id, name      FROM user     GROUP BY name );  # Step 2: Remove all rows from original table DELETE FROM user;  # Step 3: Remove all rows from original table INSERT INTO user (SELECT * FROM tmp_user);  # Step 4: Remove temporary table DROP TABLE tmp_user;

Example 5: sql query to delete duplicate records

--ID should be primary key  --get duplicate records using RANK SELECT E.ID,      E.firstname,      E.lastname,      E.country,      T.rank FROM [SampleDB].[dbo].[Employee] E   INNER JOIN (  SELECT *,          RANK() OVER(PARTITION BY firstname,                                   lastname,                                   country         ORDER BY id) rank  FROM [SampleDB].[dbo].[Employee] ) T ON E.ID = t.ID;  --delete duplications DELETE E     FROM [SampleDB].[dbo].[Employee] E          INNER JOIN     (         SELECT *,                 RANK() OVER(PARTITION BY firstname,                                          lastname,                                          country                ORDER BY id) rank         FROM [SampleDB].[dbo].[Employee]     ) T ON E.ID = t.ID     WHERE rank > 1;

Example 6: query delete duplicates

DELETE FROM dups a USING (       SELECT MIN(ctid) as ctid, key         FROM dups          GROUP BY key HAVING COUNT(*) > 1       ) b       WHERE a.key = b.key        AND a.ctid <> b.ctid