MySQL MID() Function
The MySQL MID() function is used to extract a substring from a given string.
It accepts a string value, and a numerical value specifying a position (say pos) in the string, as parameters and returns the substring of the given string starting from the specified position pos to the end of the string.
It is similar to the MySQL SUBSTRING() function but differs in that it specifies the starting position and length of the substring, rather than specifying the ending position.
Syntax
Following is the syntax of MySQL MID() function −
MID(str, pos)
Parameters
This function takes a string value and a start position as parameter.
Return Value
This function returns the substring starting from the specified position in the given string.
Another Syntax
This function also has a second syntax. In this, in addition to the string and position values it also accepts another numerical value representing the desired length (say len) of the resultant sub string.
MID(str, pos, len)
Example
In the following example, we are extracting a substring starting from position 11 to the end of the string "Welcome to Tutorialspoint" −
SELECT MID('Welcome to Tutorialspoint', 11);
Following is the output of the above code −
| MID('Welcome to Tutorialspoint', 11) |
|---|
| Tutorialspoint |
Example
In here, we are retrieving a substring starting from position 15 and having a length of 15 −
SELECT MID('Hello how are you welcome to Tutorialspoint', 15, 15);
The output obtained is as follows −
| MID('Hello how are you welcome to Tutorialspoint', 15, 15) |
|---|
| you welcome to |
Example
You can also use the FROM clause in place of commas to specify pos and len, as shown in the following examples −
SELECT ('Welcome to Tutorialspoint' FROM 11);
We get the output as follows −
| MID('Welcome to Tutorialspoint' FROM 11) |
|---|
| Tutorialspoint |
Example
The MID() function also allows you to use negative values for pos. When you use a negative pos, the resulting substring starts after the specified number of characters from the end of the given string −
SELECT MID('Welcome to Tutorialspoint' FROM -11);
Following is the output of the above code −
| MID('Welcome to Tutorialspoint' FROM -11) |
|---|
| orialspoint |
Example
You can also pass numerical values in the form of strings as the first argument to this function −
SELECT MID('67326532 7822 879282 92', 15);
The result produced is as shown below −
| MID('67326532 7822 879282 92', 15) |
|---|
| 879282 92 |
Example
If any of the arguments passed to the function is NULL, the function returns NULL −
SELECT MID(NULL, 15);
We get the output as shown below −
| MID(NULL, 15) |
|---|
| 0x |
Example
When you pass '0' as the pos parameter, the function returns an empty string −
SELECT MID('Hello how are you welcome to Tutorialspoint', 0, 15);
We get the output as follows −
| MID('Hello how are you welcome to Tutorialspoint', 0, 15) |
|---|
Example
If the argument passed as the value for the len parameter (second syntax) is less than 1, this function returns an empty string −
SELECT MID('Hello how are you welcome to Tutorialspoint', 5, -1);
Following is the output of the above code −
| MID('Hello how are you welcome to Tutorialspoint', 5, -1) |
|---|
| orialspoint |
Example
You can also get the substrings from the values of a column in a table using the MID() function.
Let us create a table named "EMP" and insert records into it using CREATE and INSERT statements as shown below −
CREATE TABLE EMP( FIRST_NAME CHAR(20) NOT NULL, LAST_NAME CHAR(20), AGE INT, INCOME FLOAT );
Now, let us insert records into it using the INSERT statement −
INSERT INTO EMP VALUES
('Krishna', 'Sharma', 19, 2000),
('Raj', 'Kandukuri', 20, 7000),
('Ramya', 'Ramapriya', 25, 5000),
('Mac', 'Mohan', 26, 2000);
The EMP obtained is as follows −
| FIRST_NAME | LAST_NAME | AGE | INCOME |
|---|---|---|---|
| Krishna | Sharma | 19 | 2000 |
| Raj | Kandukuri | 20 | 7000 |
| Ramya | Ramapriya | 25 | 5000 |
| Mac | Mohan | 26 | 2000 |
Following query retrieves substrings from the 'LAST_NAME' column using the MID() function −
SELECT FIRST_NAME, LAST_NAME, AGE, INCOME, MID(LAST_NAME, 4) FROM EMP;
Output
After executing the above code, we get the following output −
| FIRST_NAME | LAST_NAME | AGE | INCOME | MID(LAST_NAME, 4) |
|---|---|---|---|---|
| Krishna | Sharma | 19 | 2000 | rma |
| Raj | Kandukuri | 20 | 7000 | dukuri |
| Ramya | Ramapriya | 25 | 5000 | apriya |
| Mac | Mohan | 26 | 2000 | an |
Example
In the following query, we are retrieving values in 'LAST_NAME' column from pos '2' with a length of '3' −
SELECT FIRST_NAME, LAST_NAME, AGE, INCOME, MID(LAST_NAME, 2, 3) FROM EMP;
Output
The result obtained is as follows −
| FIRST_NAME | LAST_NAME | AGE | INCOME | MID(LAST_NAME, 2, 3) |
|---|---|---|---|---|
| Krishna | Sharma | 19 | 2000 | har |
| Raj | Kandukuri | 20 | 7000 | and |
| Ramya | Ramapriya | 25 | 5000 | ama |
| Mac | Mohan | 26 | 2000 | oha |