How to Get Unique Values From 2 Columns In Postgresql?

To get unique values from two columns in PostgreSQL, you can use the DISTINCT keyword with a combination of the two columns in the SELECT query. For example, if you have two columns named column1 and column2 in a table named table_name, you can retrieve unique values from both columns using the following query:

SELECT DISTINCT column1, column2 FROM table_name;

This query will return a list of unique combinations of values from column1 and column2 in the specified table. Additionally, you can use the UNION and UNION ALL operators to combine the results of two separate SELECT queries that retrieve unique values from each column individually.

How to compare unique values from two columns in PostgreSQL?

To compare the unique values from two columns in PostgreSQL, you can use a combination of the DISTINCT keyword and the UNION operator.

Here's an example query that compares the unique values from column1 and column2 in a table called your_table:

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SELECT DISTINCT column1 AS unique_values
FROM your_table
UNION
SELECT DISTINCT column2 AS unique_values
FROM your_table;

This query selects the distinct values from column1, renames the result as "unique_values", and then unions it with the distinct values from column2. This will give you a list of unique values from both columns combined.

How to extract unique values from two columns in PostgreSQL?

To extract unique values from two columns in PostgreSQL, you can use the UNION operator.

Here's an example query to extract unique values from two columns "column1" and "column2" in a table called "table1":

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SELECT column1 FROM table1
UNION
SELECT column2 FROM table1;

This query will combine the unique values from both columns into a single result set.

If you want to include NULL values from both columns, you can use the UNION ALL operator instead:

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SELECT column1 FROM table1
UNION ALL
SELECT column2 FROM table1;

This will include all values, including duplicates and NULLs.

What is the purpose of DISTINCT keyword in PostgreSQL?

The DISTINCT keyword in PostgreSQL is used in a SELECT statement to remove duplicate rows from the result set. It ensures that only unique rows are returned in the query results. This can be useful when you want to eliminate duplicate records and obtain a list of distinct values for a specific column or set of columns.

How to concatenate two columns and remove duplicates in PostgreSQL?

To concatenate two columns and remove duplicates in PostgreSQL, you can use the following query:

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SELECT DISTINCT column1 || column2 AS concatenated_columns
FROM your_table;

This query selects the concatenated values of column1 and column2 using the || operator and removes duplicates using the DISTINCT keyword. Just replace column1, column2, and your_table with the actual column names and table name in your database.

What is the function for getting unique values from two columns in PostgreSQL?

To get unique values from two columns in PostgreSQL, you can use the following query:

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SELECT DISTINCT column1, column2
FROM your_table;

This query will retrieve all unique combinations of values from column1 and column2 in the specified table.