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MySQL 칼럼 추가 1 ALTER TABLE 테이블 명 ADD COLUMN 칼럼명 CHAR(1) COMMENT '코멘트' ; cs MySQL 칼럼 삭제 1 ALTER TABLE 테이블 명 DROP COLUMN 칼럼명; cs

MySQL 문자열 함수와 연산자 WEIGHT_STRING() - WEIGHT_STRING(str [AS {CHAR | BINARY} (N)] [flags]) 의 형태 This function returns the weight string for the input string. The return value is a binary string that represents the comparison and sorting value of the string. It has these properties : If WEIGHT_STRING(str1) = WEIGHT_STRING(str2), then str1 = str2(str1 and str2 are considered equal) If WEIGHT_STRING(s..

MySQL 문자열 함수와 연산자 UPPER() - UPPER(str) 의 형태 Returns the string str with all characters changed to uppercase according to the current character set mapping. mysql> SELECT UPPER('Hej'); +--------------+ | UPPER('Hej') | +--------------+ | HEJ | +--------------+ 1 row in set (0.00 sec) UCASE() webobj.tistory.com/208 [MySQL]UCASE() MySQL 문자열 함수와 연산자 UCASE() - UCASE(str) 의 형태 UCASE() is a synonym for..

MySQL 문자열 함수와 연산자 UNHEX() - UNHEX(str) 의 형태 For a string argument str, UNHEX(str) interprets each pair of characters in the argument as a hexadecimal number and covnerts it to the byte represented by the number. The return value is a binary string. mysql> SELECT UNHEX('4D7953514C'); +---------------------+ | UNHEX('4D7953514C') | +---------------------+ | MySQL | +---------------------+ 1 row in..

MySQL 문자열 함수와 연산자 UCASE() - UCASE(str) 의 형태 UCASE() is a synonym for UPPER(). UCASE() used within views is rewritten as UPPER(). UPPER() webobj.tistory.com/210 [MySQL]UPPER() MySQL 문자열 함수와 연산자 UPPER() - UPPER(str) 의 형태 Returns the string str with all characters changed to uppercase according to the current character set mapping. mysql> SELECT UPPER('Hej').. webobj.tistory.com

MySQL 문자열 함수와 연산자 TRIM() - TRIM([{BOTH | LEADING | TRAILING} [remstr] FROM] str) TRIM([remstr FROM] str) 의 형태 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. mysql> SELECT TRIM(' bar '); +-------------------+ | TRIM(' bar ') | +-------..

MySQL 문자열 함수와 연산자 TO_BASE64() - TO_BASE64(str) 의 형태 Converts the string argument to base-64 encoded form and returns the result as a character string with the connection character set and collation. If the argument is not a string, it is converted to a string before conversion takes place. The result is NULL if the argument is NULL. Base-64 encoded strings can be docoded using the FROM_BASE64() ..

MySQL 문자열 함수와 연산자 SUBSTRING_INDEX() - SUBSTRING_INDEX(str, delim, count) 의 형태 Returns the substring from strikng str before count occurences of the delimiter delim. If count is positive, everything to the left of the final delimiter(counting from the left) is returned. If count is negative, everything to the right of the final delimter(counting from the right) is returned. SUBSTRING_INDEX() perf..

MySQL 문자열 함수와 연산자 SUBSTRING() - 문자열 자르기 정도 ? SUBSTRING(str, pos) SUBSTRING(str FROM pos) SUBSTRING(str, pos, len) SUBSTRING(str FROM pos FOR len) 의 형태 The forms without a len argument return 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 postion pos. The forms that use FROM are standard SQL syn..

MySQL 문자열 함수와 연산자 SUBSTR() - 문자열 자르기 정도 ? SUBSTR(str, pos) SUBSTR(str FROM pos) SUBSTR(str, pos, len) SUBSTR(str FROM pos FOR len) 의 형태 SUBSTR() is a synonym for SUBSTRING().

MySQL 문자열 함수와 연산자 SPACE() - SPACE(N) 의 형태 Returns a string consisting of N space characters. mysql> SELECT SPACE(6) ; +----------+ | SPACE(6) | +----------+ | | +----------+ 1 row in set (0.00 sec) mysql>

MySQL 문자열 함수와 연산자 RTRIM() - 문자열 뒷부분의 공백 제거 RTRIM(str) 의 형태 Returns the string str with trailing space characters removed. mysql> SELECT RTRIM('abcde '); +------------------+ | RTRIM('abcde ') | +------------------+ | abcde | +------------------+ 1 row in set (0.00 sec)

MySQL 문자열 함수와 연산자 RPAD() - RPAD(str, len, padstr) 의 형태 Returns the string str, right-padded with the string padstr to a length of len characters. If str is longer than len, the return value is shortened to len characters. mysql> SELECT RPAD('hello', '10', '?' ); +---------------------------+ | RPAD('hello', '10', '?' ) | +---------------------------+ | hello????? | +---------------------------+ ..

MySQL 문자열 함수와 연산자 RIGHT() - 가장 오른쪽부터 주어진 길이의 문자열을 구하는 함수 RIGHT(str, len) 의 형태 Returns the rightmost len characters from the string str, or NULL if any argument is NULL. mysql> SELECT RIGHT('abcdef', 3); +--------------------+ | RIGHT('abcdef', 3) | +--------------------+ | def | +--------------------+ 1 row in set (0.00 sec)

MySQL 문자열 함수와 연산자 REVERSE() - REVERSE(str) 의 형태 Returns the string str with the order of the characters reversed. mysql> SELECT REVERSE('abcd'); +-----------------+ | REVERSE('abcd') | +-----------------+ | dcba | +-----------------+ 1 row in set (0.00 sec)

MySQL 문자열 함수와 연산자 REPLACE() - 문자열 치환 REPLACE(str, from_str, to_str) 의 형태 Returns the string str with all occurences of the string from_str replaced by string to_str. REPLACE() performs a case-sensitive match when searching for from_str. mysql> SELECT REPLACE('오늘은 검색 오늘은', '오늘은', '내일은'); +-----------------------------------------------------------------+ | REPLACE('오늘은 검색 오늘은', '오늘은', '내일은') | +-..

MySQL 문자열 함수와 연산자 REPEAT() - 문자열 반복 REPEAT(str, count) 의 형태 Returns a string consisting of the string str repeated count times. If count is less than 1, returns an empty string. Returns NULL if str or count are NULL. mysql> SELECT REPEAT('오늘은', 5); +-----------------------------------------------+ | REPEAT('오늘은', 5) | +-----------------------------------------------+ | 오늘은오늘은오늘은오늘은오늘은 | +-------..

MySQL 문자열 함수와 연산자 QUOTE() - QUOTE(str) 의 형태 Quotes a string to produce a result that can be used as a property escaped data value in an SQL statement. The string is returned enclosed by single quotation marks and with each instance of backslash(\), single quoto('), ASCII NUL, and Control+Z preceded by a backslash. If the argument is NULL, the return value is the world "NULL" without enclosing si..

MySQL 문자열 함수와 연산자 POSITION() - POSITION(substr IN str) 의 형태 POSITION(substr IN str) is synonym for LOCATE(substr, str). https://webobj.tistory.com/184 [MySQL] LOCATE() MySQL 문자열 함수와 연산자 LOCATE() - LOCATE(substr, str) LOCATE(substr, str, pos) 의 형태 The first syntax returns the position of the first occurence of substring substr in string str. The second.. webobj.tistory.com

MySQL 문자열 함수와 연산지 ORD() - ORD(str) 의 형태 If the leftmost character of the string str is a multibyte character, returns the code for that character, calculated from the numeric values of its constituent bytes using this formula : (1st bye code) + (2nd byte code * 256) + (3rd byte code * 256^2).... If the leftmost character is not a multibyte character, ORD() returns the same value as the ASCII() f..