字符串函数43个
函数名 函数种类 返回值的类型 参数个数(-1表示可变参数) nullIfParameterIsNull deterministic fast
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ASCII 50 INTEGER 1 true true false
BIT_LENGTH 51 BIGINT 1 true true false
CHAR 52 VARCHAR 1 true true false CHR 52 VARCHAR 1 true true false 与前面相同
CHAR_LENGTH 53 INTEGER 1 true true false CHARACTER_LENGTH 53 INTEGER 1 true true false 与前面相同
CONCAT 54 VARCHAR -1 false true false
CONCAT_WS 92 VARCHAR -1 false true false
DIFFERENCE 55 INTEGER 2 true true false
HEXTORAW 56 VARCHAR 1 true true false
INSERT 57 VARCHAR 4 false true false
LCASE 59 VARCHAR 1 true true false
LEFT 60 VARCHAR 2 true true false
LENGTH 61 BIGINT 1 true true false
LOCATE 62 INTEGER -1 true true false
POSITION 77 INTEGER 2 true true false
INSTR 58 INTEGER -1 true true false
LTRIM 63 VARCHAR -1 true true false
OCTET_LENGTH 64 BIGINT 1 true true false
RAWTOHEX 65 VARCHAR 1 true true false
REPEAT 66 VARCHAR 2 true true false
REPLACE 67 VARCHAR -1 true true false
RIGHT 68 VARCHAR 2 true true false
RTRIM 69 VARCHAR -1 true true false
SOUNDEX 70 VARCHAR 1 true true false
SPACE 71 VARCHAR 1 true true false
SUBSTR 72 VARCHAR -1 true true false
SUBSTRING 73 VARCHAR -1 true true false
UCASE 74 VARCHAR 1 true true false
LOWER 75 VARCHAR 1 true true false
UPPER 76 VARCHAR 1 true true false
TRIM 78 VARCHAR -1 true true false
STRINGENCODE 79 VARCHAR 1 true true false
STRINGDECODE 80 VARCHAR 1 true true false
STRINGTOUTF8 81 VARBINARY 1 true true false
UTF8TOSTRING 82 VARCHAR 1 true true false
XMLATTR 83 VARCHAR 2 true true false
XMLNODE 84 VARCHAR -1 false true false
XMLCOMMENT 85 VARCHAR 1 true true false
XMLCDATA 86 VARCHAR 1 true true false
XMLSTARTDOC 87 VARCHAR 0 true true false
XMLTEXT 88 VARCHAR -1 true true false
REGEXP_REPLACE 89 VARCHAR 3 true true false
RPAD 90 VARCHAR -1 true true false
LPAD 91 VARCHAR -1 true true false