How do I count distinct values in a case statement in SQL?

You can try this: select count(distinct tag) as tag_count, count(distinct (case when entryId > 0 then tag end)) as positive_tag_count from your_table_name; The first count(distinct…) is easy.

Can we use distinct in case statement in SQL?

In general whenever we have to use ‘distinct’ clause along with case statement, it always resides outside the case statement unless we are using a sub-query in the case statement. If we put ‘distinct’ clause inside case statement, we will get ora-00936, missing expression error.

How do I count distinct values in SQL query?

To count the number of different values that are stored in a given column, you simply need to designate the column you pass in to the COUNT function as DISTINCT . When given a column, COUNT returns the number of values in that column. Combining this with DISTINCT returns only the number of unique (and non-NULL) values.

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Can count be used with distinct?

Yes, you can use COUNT() and DISTINCT together to display the count of only distinct rows. SELECT COUNT(DISTINCT yourColumnName) AS anyVariableName FROM yourTableName; To understand the above syntax, let us create a table. Display all records from the table using select statement.

How do I count distinct groups in SQL?

COUNT(ALL expression) evaluates expression for each row in a group, and returns the number of nonnull values. COUNT(DISTINCT expression) evaluates expression for each row in a group, and returns the number of unique, nonnull values. For return values exceeding 2^31-1, COUNT returns an error.

In which part of the SQL statement do you include distinct?

The SQL DISTINCT keyword is used in conjunction with the SELECT statement to eliminate all the duplicate records and fetching only unique records. There may be a situation when you have multiple duplicate records in a table.

What is the difference between unique and distinct in SQL?

The main difference between Unique and Distinct in SQL is that Unique helps to ensure that all the values in a column are different while Distinct helps to remove all the duplicate records when retrieving the records from a table.

Does distinct count NULL values?

COUNT DISTINCT does not count NULL as a distinct value. … The ALL keyword counts all non-NULL values, including all duplicates. ALL is the default behavior if no keyword is specified.

How do I use distinct in one column in SQL?

Adding the DISTINCT keyword to a SELECT query causes it to return only unique values for the specified column list so that duplicate rows are removed from the result set. Since DISTINCT operates on all of the fields in SELECT’s column list, it can’t be applied to an individual field that are part of a larger group.

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How do I find the distinct value of a table?


The SELECT DISTINCT statement is used to return only distinct (different) values. Inside a table, a column often contains many duplicate values; and sometimes you only want to list the different (distinct) values.

Does Count distinct * Works in SQL?

SQL COUNT() function with DISTINCT clause eliminates the repetitive appearance of the same data. The DISTINCT can come only once in a given select statement. We can’t DISTINCT be used with COUNT(*) in SQL as data will lost. distinct – refers to the unique records ( of all columns ) among the rows fetched.

What is the difference between Count Count distinct and count (*) in SQL When will these three commands generate the same and different results?

The simple answer is no – there is no difference at all. The COUNT(*) function counts the total rows in the table, including the NULL values. The semantics for COUNT(1) differ slightly; we’ll discuss them later. However, the results for COUNT(*) and COUNT(1) are identical.

What does distinct count mean?

Count is the total number of values. Count Distinct in the number of unique values. Count Distinct will always be equal to or less than Count. Helpful (0) Count is the total number of values.