今天分享几个关于MySQL数据类型的查询,具体如下:
在 MySQL 数据库中查找最常用的数据类型查找 MySQL 数据库中的所有数字列查找 MySQL 数据库中的所有字符串(字符)列查找 MySQL 数据库中的所有日期和时间列查找 MySQL 数据库中的所有枚举列查找 MySQL 数据库中的所有空间数据列查找 MySQL 数据库中的所有 JSON 数据列在 MySQL 数据库中查找大对象 (LOB) 数据类型列在 MySQL 数据库中查找具有大对象 (LOB) 数据类型列的表select data_type, count(*) as columns, cast(100*count(*)/sum_all.columns as decimal(36,2)) as percent_columns, count(distinct concat(col.table_schema, '.', col.table_name)) as tables, cast(100*count(distinct concat(col.table_schema,'.',col.table_name)) / sum_all.tables as decimal(36,2)) as percent_tables from information_schema.columns col join (select count(distinct concat(c.table_schema, '.', c.table_name)) as tables, count(*) as columns from information_schema.columns c join information_schema.tables t on c.table_schema = t.table_schema and c.table_name = t.table_name where t.table_schema not in ('information_schema', 'mysql', 'performance_schema', 'sys') and t.table_type = 'BASE TABLE' ) sum_all on true join information_schema.tables tab on col.table_schema = tab.table_schema and col.table_name = tab.table_name where tab.table_schema not in ('information_schema', 'mysql', 'performance_schema', 'sys') and tab.table_type = 'BASE TABLE' group by data_type, sum_all.columns, sum_all.tables order by columns desc;
说明:
data_type - 没有长度或精度的内置或用户数据类型,例如 int、varchar 或 datetimecolumns - 具有此数据类型的数据库(模式)中的列数percent_columns - 具有此数据类型的列的百分比。行总数为 100%tables- 数据库(模式)中具有此数据类型的表数percent_tables - 具有此数据类型的列的表的百分比。select col.table_schema as database_name, col.table_name, col.ordinal_position as col_id, col.column_name, col.data_type, col.numeric_precision, col.numeric_scale from information_schema.columns col join information_schema.tables tab on tab.table_schema = col.table_schema and tab.table_name = col.table_name and tab.table_type = 'BASE TABLE' where col.data_type in ('tinyint', 'smallint', 'mediumint', 'int', 'bigint', 'decimal', 'bit', 'float', 'double') and col.table_schema not in ('information_schema', 'sys', 'performance_schema', 'mysql') --and col.table_schema = 'database_name' -- put your database name here order by col.table_schema, col.table_name, col.ordinal_position;
说明:
database_name - 数据库的名称(模式)table_name - 表的名称column_id - 表中的列位置column_name - 列的名称data_type - 数据类型numeric_precision - 列的精度numeric_scale - 列的比例select col.table_schema as database_name, col.table_name, col.ordinal_position as column_id, col.column_name, col.data_type, col.character_maximum_length as maximum_length, col.character_set_name from information_schema.columns col join information_schema.tables tab on tab.table_schema = col.table_schema and tab.table_name = col.table_name and tab.table_type = 'BASE TABLE' where col.data_type in ('char', 'varchar', 'binary', 'varbinary', 'blob', 'tinyblob', 'mediumblob', 'longblob', 'text', 'tinytext', 'mediumtext', 'longtext' 'enum', 'set') and col.table_schema not in ('information_schema', 'sys', 'performance_schema', 'mysql') --and col.table_schema = 'database_name' -- put your database name here order by col.table_schema, col.table_name, col.ordinal_position;
说明:
database_name - 数据库的名称(模式)table_name - 表的名称column_id - 表中的列位置column_name - 列的名称data_type - 数据类型maximum_length - 字符的最大长度character_set_name - 字符集名称来源:https://www.51cto.com/article/712988.html