首先遇到问题,第一想到的就是官方找答案,我们翻阅官方文档,关于float和double有这样一段描述 For FLOAT, the SQL standard permits an optional specification of the precision (but not the range of the exponent) in bits following the keywordFLOAT in parentheses. MySQL also supports this optional precision ...
1 row in set (0.00 sec) mysql> drop table fl; Query OK, 0 rows affected (0.00 sec) mysql> CREATE TABLE `fl` ( -> `id` int(11) DEFAULT NULL, -> `fl` float(25,23) DEFAULT NULL -> ) ENGINE=MyISAM DEFAULT CHARSET=utf8; Query OK, 0 rows affected (0.02 sec) mysql> show cr...
mysql> set session transaction isolation level serializable -> ; Query OK, 0 rows affected (0.00 sec) mysql> select @@tx_isolation; +---+ | @@tx_isolation | +---+ | SERIALIZABLE | +---+ 1 row in set (0.00 sec) mysql> start transaction -> ; Query OK, 0 rows affected (0.00 ...
mysql> insert into t1 values(1234567.23, 1234567.23); Query OK, 1 row affected (0.01 sec) mysql> select * from t1; +———+———+ | c1 | c3 | +———+———+ | 1234567.25 | 1234567.23 | +———+———+ 1 row in set (0.02 sec) mysql> insert into t1 values(9876543.21, 98...
For FLOAT, the SQL standard permits an optional specification of the precision (but not the range of the exponent) in bits following the keywordFLOAT in parentheses. MySQL also supports this optional precision specification, but the precision value is used only to determine storage size. A precisi...
For FLOAT, the SQL standard permits an optional specification of the precision (but not the range of the exponent) in bits following the keywordFLOAT in parentheses. MySQL also supports this optional precision specification, but the precision value is used only to determine storage size. A precisi...
```sql mysql> create table t1(c1 float(10,2), c3 decimal(10,2));Query OK, 0 rows affected (0.02 sec)mysql> insert into t1 values(9876543.21, 9876543.12);Query OK, 1 row affected (0.00 sec)mysql> select from t1;| c1 | c3 | | 9876543.00 | 9876543.12 | 2 rows in set...
void RetrieveFloatValue() { _RecordsetPtr pRst("ADODB.Recordset"); pRst->Open(sqlQuery.AllocSysString(), pConn.GetInterfacePtr(), adOpenKeyset, adLockOptimistic, adCmdText); if (!pRst->EOF) { while (!pRst->EndOfFile) { // Assuming MyFloatColumn is of type float in the data...
1 row in set (0.00 sec) 注:小数位数不够,自动补齐,但是存在一个问题就是如上的近似值。 mysql> insert into tt(num)values(123456.867); Query OK, 1 row affected (0.04 sec) mysql> select * from tt; +---+ | num | +---+ | 123456.797...
创建表时使用的float(12)类型,在用desc显示表的信息时显示为float,float(25),直接显示为double,可以看出,只指定精度,MySQL数据库会根据指定的精度选择float或者double类型。如果时同时指定精度和刻度呢,加一列看一下: mysql>altertablet_f add salaryfloat(10,2);Query OK,0rows affected,1warning(0.09sec)Records...