user=user,password=password,database=database)try:withconnection.cursor()ascursor:sql="SELECT my_blob_column FROM my_table WHERE id = %s"cursor.execute(sql,(1,))# 假设我们需要 id = 1 的记录result=cursor.fetchone()#
1. 查询 Blob 字段 首先,我们需要查询数据库中的 Blob 字段。以下是示例代码: SELECTblob_fieldFROMtable_nameWHEREcondition; 1. 注释:这条 SQL 语句用于查询表中的 Blob 字段。 2. 将 Blob 字段转换为字符串 接下来,我们需要将查询到的 Blob 字段转换为字符串。以下是示例代码: importbase64defblob_to_str...
使用CONVERT函数: sql SELECT CONVERT(blob_field USING utf8) AS string_field FROM table_name WHERE condition; 这种方法可以指定字符集(如utf8),从而更准确地处理编码问题。但需要注意的是,如果BLOB数据不是文本数据(如图像、视频等),转换后可能会显示为乱码或Null。 使用TO_BASE64和FROM_BASE64函数(MySQL...
I have a String and I am trying to convert that String into BLOB, sothat I can insert that blob into the database table. SO what I did is I converted String to byte array and when I am trying to insert into the table which has a field, blob as datatype, it is giving me the ...
blob 二进制流类型 enum 枚举 插入值时 对应的值 必须在枚举中存在 二常用的数据库函数 字符串类 CHARSET(str) //返回字串字符集 CONCAT (string2 [,... ]) //连接字串 INSTR (string ,substring ) //返回substring首次在string中出现的位置,不存在返回0 ...
MySQL中，BLOB是个类型系列，包括：TinyBlob、Blob、MediumBlob、LongBlob，这几个类型之间的唯一区别是在...
The MySQL protocol is a text-based protocol. This means that over the wire, all field types are represented as a string, which is why only string-like functions are available on thefieldobject. Based on the type information (likeINT), the type cast should convert the string field into a...
CONVERT(R) CPU CREATE(R) CROSS(R) CUBE CURRENT CURRENT_DATE(R) CURRENT_TIME(R) CURRENT_TIMESTAMP(R) CURRENT_USER(R) CURSOR(R) CURSOR_NAME DATA DATABASE(R) DATABASES(R) DATAFILE DATE DATETIME DAY DAY_HOUR(R) DAY_MICROSECOND(R) ...
使用类型转换函数(如CAST或CONVERT)将参数转换为正确的类型。 代码语言:txt 复制 SELECT * FROM users WHERE age BETWEEN CAST(? AS SIGNED) AND CAST(? AS SIGNED) AND email LIKE ?; 问题:SQL注入风险 原因:直接将用户输入拼接到SQL查询中,存在SQL注入的风险。 解决方法: 使用参数化查询(如上例中的?占位...
I need to convert it into another column type which doesn't have this performance penalty. So is there a way to convert this field automatically? Subject Written By Posted Converting a blob field into varchar Mario Bittencourt February 12, 2013 12:38PM ...