1.字符型：
sql-92: char,varchar
mysql:char,varchar & & binary,varbinary
mssql: char,varchar & nchar,nvarchar & binary,varbinary
oracle: char, varchar2(varchar), raw, nchar, nvarchar2,
注：varchar,raw必须设定大小
2.文本型
mysql: tinytext, text, mediumtext, and longtext & tinyblob, blob, mediumblob, and longblob
mssql: text & ntext & image
oracle: long, long raw, clob, nlob, blob, bfile
3.数值型
3.1整数int
sql-92: int, smallint
mysql: tinyint, smallint, mediumint, int, bigint
mssql: tinyint, smallint, int, bigint
oracle:
3.2小数numeric
sql-92: numeric, float, real(double precision)
mysql:float, double, decimal(dec)
mssql: numeric(decimal), float, real
oracle:number, binary_float, binary_double,
3.3货币money
sql-92:
mysql:numeric(decimal),float,real
mssql: money,smallmoney
oracle:
4.逻辑型
sql-92:
mysql:bool(boolean)
mssql: bit
oracle:
5.日期型
sql-92: date,time
mysql:date,datetime,timestamp,time,year
mssql: datetime,smalldatetime,timestamp
oracle:timestamp, timestamp with time zone, timestamp with local time zone, interval year to month, interval day to second
