Question

我使用关键字和存储在base64encoded字符串中的关键字进行搜索功能。我该如何搜索该关键字？

示例：我在文本框中输入he进行搜索...我在列中有多个值，如

he - aGU=

hea - aGVh

不同的子串具有不同的base64encode字符串

bXkgaGVhbHRo  - my Health

aGVhbHRoIGlzIGdvb2Q= - health is good

我在查询中使用了LIKE

SELECT * FROM tblname WHERE texting LIKE '%aGU=%'

我试过了

TO_BASE64(str) and FROM_BASE64() but it works on 5.6.1 and i have version 5.0.7

怎么可能？

Answer 1

在MySQL 5.6.1中。

使用TO_BASE64(str)和FROM_BASE64()

参见mysql doc：

http://dev.mysql.com/doc/refman/5.6/en/string-functions.html#function_to-base64

替代MYSQL功能

delimiter |

DROP TABLE IF EXISTS base64_data |
CREATE TABLE base64_data (c CHAR(1) BINARY, val TINYINT) |
INSERT INTO base64_data VALUES 
    ('A',0), ('B',1), ('C',2), ('D',3), ('E',4), ('F',5), ('G',6), ('H',7), ('I',8), ('J',9),
    ('K',10), ('L',11), ('M',12), ('N',13), ('O',14), ('P',15), ('Q',16), ('R',17), ('S',18), ('T',19),
    ('U',20), ('V',21), ('W',22), ('X',23), ('Y',24), ('Z',25), ('a',26), ('b',27), ('c',28), ('d',29),
    ('e',30), ('f',31), ('g',32), ('h',33), ('i',34), ('j',35), ('k',36), ('l',37), ('m',38), ('n',39),
    ('o',40), ('p',41), ('q',42), ('r',43), ('s',44), ('t',45), ('u',46), ('v',47), ('w',48), ('x',49),
    ('y',50), ('z',51), ('0',52), ('1',53), ('2',54), ('3',55), ('4',56), ('5',57), ('6',58), ('7',59),
    ('8',60), ('9',61), ('+',62), ('/',63), ('=',0) |


DROP FUNCTION IF EXISTS BASE64_DECODE |
CREATE FUNCTION BASE64_DECODE (input BLOB)
    RETURNS BLOB
    CONTAINS SQL
    DETERMINISTIC
    SQL SECURITY INVOKER
BEGIN
    DECLARE ret BLOB DEFAULT '';
    DECLARE done TINYINT DEFAULT 0;

    IF input IS NULL THEN
        RETURN NULL;
    END IF;

each_block:
    WHILE NOT done DO BEGIN
        DECLARE accum_value BIGINT UNSIGNED DEFAULT 0;
        DECLARE in_count TINYINT DEFAULT 0;
        DECLARE out_count TINYINT DEFAULT 3;

each_input_char:
        WHILE in_count < 4 DO BEGIN
            DECLARE first_char CHAR(1);

            IF LENGTH(input) = 0 THEN
                RETURN ret;
            END IF;

            SET first_char = SUBSTRING(input,1,1);
            SET input = SUBSTRING(input,2);

            BEGIN
                DECLARE tempval TINYINT UNSIGNED;
                DECLARE error TINYINT DEFAULT 0;
                DECLARE base64_getval CURSOR FOR SELECT val FROM base64_data WHERE c = first_char;
                DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET error = 1;

                OPEN base64_getval;
                FETCH base64_getval INTO tempval;
                CLOSE base64_getval;

                IF error THEN
                    ITERATE each_input_char;
                END IF;

                SET accum_value = (accum_value << 6) + tempval;
            END;

            SET in_count = in_count + 1;

            IF first_char = '=' THEN
                SET done = 1;
                SET out_count = out_count - 1;
            END IF;
        END; END WHILE;

        -- We've now accumulated 24 bits; deaccumulate into bytes

        -- We have to work from the left, so use the third byte position and shift left
        WHILE out_count > 0 DO BEGIN
            SET ret = CONCAT(ret,CHAR((accum_value & 0xff0000) >> 16));
            SET out_count = out_count - 1;
            SET accum_value = (accum_value << 8) & 0xffffff;
        END; END WHILE;

    END; END WHILE;

    RETURN ret;
END |

DROP FUNCTION IF EXISTS BASE64_ENCODE |
CREATE FUNCTION BASE64_ENCODE (input BLOB)
    RETURNS BLOB
    CONTAINS SQL
    DETERMINISTIC
    SQL SECURITY INVOKER
BEGIN
    DECLARE ret BLOB DEFAULT '';
    DECLARE done TINYINT DEFAULT 0;

    IF input IS NULL THEN
        RETURN NULL;
    END IF;

each_block:
    WHILE NOT done DO BEGIN
        DECLARE accum_value BIGINT UNSIGNED DEFAULT 0;
        DECLARE in_count TINYINT DEFAULT 0;
        DECLARE out_count TINYINT;

each_input_char:
        WHILE in_count < 3 DO BEGIN
            DECLARE first_char CHAR(1);

            IF LENGTH(input) = 0 THEN
                SET done = 1;
                SET accum_value = accum_value << (8 * (3 - in_count));
                LEAVE each_input_char;
            END IF;

            SET first_char = SUBSTRING(input,1,1);
            SET input = SUBSTRING(input,2);

            SET accum_value = (accum_value << 8) + ASCII(first_char);

            SET in_count = in_count + 1;
        END; END WHILE;

        -- We've now accumulated 24 bits; deaccumulate into base64 characters

        -- We have to work from the left, so use the third byte position and shift left
        CASE
            WHEN in_count = 3 THEN SET out_count = 4;
            WHEN in_count = 2 THEN SET out_count = 3;
            WHEN in_count = 1 THEN SET out_count = 2;
            ELSE RETURN ret;
        END CASE;

        WHILE out_count > 0 DO BEGIN
            BEGIN
                DECLARE out_char CHAR(1);
                DECLARE base64_getval CURSOR FOR SELECT c FROM base64_data WHERE val = (accum_value >> 18);

                OPEN base64_getval;
                FETCH base64_getval INTO out_char;
                CLOSE base64_getval;

                SET ret = CONCAT(ret,out_char);
                SET out_count = out_count - 1;
                SET accum_value = accum_value << 6 & 0xffffff;
            END;
        END; END WHILE;

        CASE
            WHEN in_count = 2 THEN SET ret = CONCAT(ret,'=');
            WHEN in_count = 1 THEN SET ret = CONCAT(ret,'==');
            ELSE BEGIN END;
        END CASE;

    END; END WHILE;

    RETURN ret;
END |

来自

如何在mysql中搜索base64encoded字符串？

1 个答案: