String function in my sql
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The document outlines various string types in MySQL, including fixed-length 'char' and variable-length 'varchar', along with essential string functions such as concat(), instr(), and lcase(). It describes how each function operates and provides examples of their usage in SQL queries. Additionally, it explains the behavior of functions that manipulate string data, focusing on aspects like length, trimming, and case conversion.
![TRIM([remstr FROM] str)
Returns the string str with all remstr prefixes or
suffixes removed. If none of the specifiers BOTH,
LEADING, or TRAILING is given, BOTH is
assumed. remstr is optional and, if not
specified, spaces are removed.
TRIM(‘ bar ‘);
TRIM(‘ bar ‘)
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String function in my sql
- 1. STRING FUNCTION IN MYSQL
- 2. STRING TYPES CHAR(M) - A fixed-length string between 1 and 255 characters in length (for example CHAR(5)), right-padded with spaces to the specified length when stored. Defining a length is not required, but the default is 1. VARCHAR(M) - A variable-length string between 1 and 255 characters in length; for example VARCHAR(25). You must define a length when creating a VARCHAR field.
- 3. String Functions CONCAT() Return concatenated string INSTR() Return the index of the first occurrence of substring LCASE() Synonym for LOWER() LEFT() Return the leftmost number of characters as specified LENGTH() Return the length of a string in bytes LOWER() Return the argument in lowercase LTRIM() Remove leading spaces MID() Return a substring starting from the specified position RIGHT() Return the specified rightmost number of characters RTRIM() Remove trailing spaces SUBSTRING(), Return the substring as specified SUBSTR() TRIM() Remove leading and trailing spaces UCASE() Synonym for UPPER() UPPER() Convert to uppercase
- 4. CONCAT(str1,str2,...) Returns the string that results from concatenating the arguments. May have one or more arguments. If all arguments are non-binary strings, the result is a non-binary string. If the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent binary string form; if you want to avoid that, you can use an explicit type cast, as in this example: mysql> SELECT CONCAT('My', 'S', 'QL'); +-----------------------------------------------------------------------------+ | CONTACT (‘My’, ‘S’, ‘QL’) | +-----------------------------------------------------------------------------+ | MySQL | +-----------------------------------------------------------------------------+ 1 row in set (0.00 sec)
- 5. INSERT(str,pos,len,newstr) Returns the string str, with the substring beginning at position pos and len characters long replaced by the string newstr. Returns the original string if pos is not within the length of the string. Replaces the rest of the string from position pos if len is not within the length of the rest of the string. Returns NULL if any argument is NULL. mysql> SELECT INSERT('Quadratic', 3, 4, 'What'); +-----------------------------------------------------------------------------+ | INSERT('Quadratic', 3, 4, 'What') | +-----------------------------------------------------------------------------+ | QuaWhatic | +-----------------------------------------------------------------------------+ 1 row in set (0.00 sec)
- 6. LCASE(str) LCASE() is a synonym for LOWER(). LEFT(str,len) Returns the leftmost len characters from the string str, or NULL if any argument is NULL. mysql> SELECT LEFT('foobarbar', 5); +-----------------------------------------------------------------------------+ | LEFT('foobarbar', 5) | +-----------------------------------------------------------------------------+ | fooba | +-----------------------------------------------------------------------------+ 1 row in set (0.00 sec)
- 7. LENGTH(str) Returns the length of the string str, measured in bytes. A multi-byte character counts as multiple bytes. This means that for a string containing five two-byte characters, LENGTH() returns 10, whereas CHAR_LENGTH() returns 5. LENGTH('text'); LENGTH('text') 4
- 8. LOWER(str) Returns the string str with all characters changed to lowercase according to the current character set mapping. LOWER(‘QUADRATICALLY'); LOWER(‘QUADRATICALLY') quadratically
- 9. LTRIM(str) Returns the string str with leading space characters removed. LTRIM(‘ barbar’); LTRIM(‘ barbar') barbar
- 10. RIGHT(str,len) Returns the rightmost len characters from the string str, or NULL if any argument is NULL. RIGHT (‘foobarbar’); RIGHT(‘foobarbar') rbar
- 11. MID(str,pos,len) and SUBSTRING(str , pos, len) The forms without a len argument return a substring from string str starting at position pos. The forms with a len argument return a substring len characters long from string str, starting at position pos. The forms that use FROM are standard SQL syntax. It is also possible to use a negative value for pos. In this case, the beginning of the substring is pos characters from the end of the string, rather than the beginning. A negative value may be used for pos in any of the forms of this function. SUBSTRING(‘quadratically’, 5, 6); SUBSTRING(‘quadratically’, 5, 6) ratica
- 12. TRIM([remstr FROM] str) Returns the string str with all remstr prefixes or suffixes removed. If none of the specifiers BOTH, LEADING, or TRAILING is given, BOTH is assumed. remstr is optional and, if not specified, spaces are removed. TRIM(‘ bar ‘); TRIM(‘ bar ‘) bar
- 13. UCASE(str) and UPPER(str) • UCASE() is a synonym for UPPER(). • Returns the string str with all characters changed to uppercase according to the current character set mapping. UPPER('Allah-hus-samad'); UPPER('Allah-hus-samad') ALLAH-HUS-SAMAD
- 14. THANK YOU