select TABLE_SCHEMA dbName from information_schema.tables group by TABLE_SCHEMA
select table_name tableName, table_comment as tableComment from information_schema.tables where table_schema=#{dbName}
SELECT COLUMN_NAME NAME,column_comment DESCRIPTION,column_type TYPE,if(is_nullable='YES',1,0) NULLABLE FROM INFORMATION_SCHEMA.Columns WHERE table_schema=#{dbName} AND table_name=#{tableName} ORDER BY ordinal_position
select 1
SELECT TABLE_NAME, COLUMN_NAME, column_comment DESCRIPTION FROM INFORMATION_SCHEMA.Columns WHERE table_schema=#{dbName} AND (COLUMN_NAME like #{searchText} or column_comment like #{searchText})
select table_name tableName, table_comment as description from information_schema.tables where table_name=#{tableName}
alter table ${dbName}.${tableName} comment #{newDesc}
alter table ${dbName}.${tableName} modify column ${columnName} ${columnInfo.columnType} ${columnInfo.isNullable} ${columnInfo.columnDefault} ${columnInfo.extra} comment #{newDesc}