How do I count unique values in SQL?

How do I count unique values in SQL?

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.

How do you count unique values?

You can use the combination of the SUM and COUNTIF functions to count unique values in Excel. The syntax for this combined formula is = SUM(IF(1/COUNTIF(data, data)=1,1,0)). Here the COUNTIF formula counts the number of times each value in the range appears.

How do I sum a column in SQL?

The SUM() function returns the total sum of a numeric column.

  1. COUNT() Syntax. SELECT COUNT(column_name) FROM table_name. WHERE condition;
  2. AVG() Syntax. SELECT AVG(column_name) FROM table_name. WHERE condition;
  3. SUM() Syntax. SELECT SUM(column_name) FROM table_name. WHERE condition;

How do I do an if statement in SQL?

Syntax. In the following SQL IF Statement, it evaluates the expression, and if the condition is true, then it executes the statement mentioned in IF block otherwise statements within ELSE clause is executed. We can understand SQL IF Statement using the following flow chart.

How use multiple IF condition in SQL query?

If you are checking conditions against multiple variables then you would have to go for multiple IF Statements, Each block of code will be executed independently from other blocks. ELSE IF(@ID IS NOT NULL AND @ID in (SELECT ID FROM Places)) -- Outer Most Block ELSE IF BEGIN SELECT @MyName = Name ... ...

Is null or empty SQL?

There are two ways to replace NULL with blank values in SQL Server, function ISNULL(), and COALESCE(). Both functions replace the value you provide when the argument is NULL like ISNULL(column, '') will return empty String if the column value is NULL.

How many else clauses can an if statement have?

No, there can be only one else per if . Since an else if is a new if , it can have a new else - you can have as many else if s as you want. No, you can put any condition in any if statement: if (foo) ... else if (bar) ...

What is nested IF statement?

A nested if statement is an if-else statement with another if statement as the if body or the else body. Here's an example: ... If the outer if condition evaluates to true, evaluate the outer if condition.

How do you write an IF-THEN statement?

Another way to define a conditional statement is to say, “If this happens, then that will happen.” The hypothesis is the first, or “if,” part of a conditional statement. The conclusion is the second, or “then,” part of a conditional statement. The conclusion is the result of a hypothesis.

What is the if statement syntax?

The syntax for if statement is as follows: if (condition) instruction; The condition evaluates to either true or false. True is always a non-zero value, and false is a value that contains zero.

What are the 3 types of control structures?

Flow of control through any given function is implemented with three basic types of control structures:

  • Sequential: default mode. ...
  • Selection: used for decisions, branching -- choosing between 2 or more alternative paths. ...
  • Repetition: used for looping, i.e. repeating a piece of code multiple times in a row.

What is if statement use?

The if statement is used to check a condition and if the condition is true, we run a block of statements (called the if-block), else we process another block of statements (called the else-block). The else clause is optional.

What is if statement in Java?

The Java if statement is the most simple decision-making statement. It is used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.

Can we use only if without else?

An if statement looks at any and every thing in the parentheses and if true, executes block of code that follows. If you require code to run only when the statement returns true (and do nothing else if false) then an else statement is not needed.

What is if condition in C++?

The if statement allows you to control if a program enters a section of code or not based on whether a given condition is true or false. One of the important functions of the if statement is that it allows the program to select an action based upon the user's input.

What does && mean in C++?

logical AND operator

What is C++ syntax?

The term “Syntax” is a set of pre-defined protocols or rules that we need to follow in a programming language. Every programming language has its own unique syntax. Similarly, C++ Syntax also has its significance.

What does == mean in C++?

The equal-to operator ( == ) returns true if both operands have the same value; otherwise, it returns false . The not-equal-to operator ( != ) returns true if the operands don't have the same value; otherwise, it returns false .

What is the difference between I 10 & I == 10?

'a=10' is used to assign the value of 10 in 'a' variable whereas 'a==10' compare the value of 'a' variable with 10. Explanation: In "a=10", a is a variable that is initialized by 10 value because in any programming language "=" stands for assignment operator which is used to assign the value for any variable.

What does * do in C++?

It means that you're passing it a pointer to a character, which usually means that pointer points to the first character in an array of characters. With a pointer ( * ), you can do arithmetic, e.g. (fileName + 1) to get the second character.

What C Day means?

Definition. C-day. unnamed day on which a deployment operation begins (US DoD)

What does C mean in text speak?

"Very Happy" is the most common definition for C: on Snapchat, WhatsApp, Facebook, Twitter, and Instagram. C: Definition: Very Happy.

What is happy G day?

Description. Happy G day is the new phrase to wish happy birthday. It actually narrates happy golden day. Also, it is used to greet and welcome friends or associates.

What does CS mean on Snapchat?

Riot Control Gas

What is CS short?

AcronymDefinition
CSComing Soon
CSComputer Software
CSComputer Services
CSCross Section

What does SC stand for?

AcronymDefinition
SCSouth Carolina (US postal abbreviation)
SCSupply Chain
SCStudent Center
SCSmall Capital (letter)