获取数据库其中某个表的结构

SQL

SELECT sys.objects.name name,sys.columns.name col,max_length long

  FROM sys.objects join sys.columns on sys.objects.object_id=sys.columns.object_id
  where sys.objects.name='lrwf00h' and sys.columns.name='wf_text'
    --WHERE type='U'

    --  ORDER BY 1,2

SELECT LEN(wf_text) as wf_textlong ,* FROM lrwf00h 
WHERE  LEN(wf_text)>800

MYSQL 

mysql< DESCRIBE tableName;
mysql< DESCRIBE tableName columnName;
mysql< DESC tableName;
mysql< SHOW COLUMNS FROM tableName;

DESCRIBE lrwf00h wf_text

SELECT CHAR_LENGTH(wf_text) AS wf_textlong FROM lrwf00h 
WHERE  CHAR_LENGTH(wf_text)>800


SELECT CHAR_LENGTH(wf_text) AS wf_textlong FROM lrwf00h WHERE wf_text