<?xml version="1.0" encoding="GB2312"?>
<Express>
   <常规>
      <Item>and</Item>
      <Item>or</Item>
      <Item>(</Item>
      <Item>)</Item>
      <Item>not</Item>
      <Item>=</Item>
      <Item>&lt;&gt;</Item>
      <Item>&gt;</Item>
      <Item>&lt;</Item>
      <Item>&gt;=</Item>
      <Item>&lt;=</Item>
      <Item>+</Item>
      <Item>-</Item>
      <Item>*</Item>
      <Item>/</Item>
      <Item>Range|判断值是否位于两者的闭区间之间，示例Range 1-100</Item>
      <Item>OutRange|判断值是否位于两者的闭区间之外，示例OutRange 1-100</Item>
      <Item>Contain|判断值是否包含指定字符，示例Contain -, Contain C-G</Item>
      <Item>NotContain|判断值是否未包含指定字符，示例NotContain -</Item>
      <Item>Like|判断值是否相似于指定字符串，示例Like Data*, Like Data??</Item>
      <Item>NotLike|判断值是否不相似于指定字符串，示例NotLike Data*, Like Data??</Item>
      <Item>In|判断值是否在指定字符串组中，示例In 1, 2, 3, In AB, CD, EF</Item>
      <Item>NotIn|判断值是否不在指定字符串组中，示例NotIn 1, 2, 3, NotIn AB, CD, EF</Item>
   </常规>
   <SQL>
      <Item>select * from|选择数据,示例select column1, column2 from TableName</Item>
      <Item>update set|更新数据,示例update TableName set Field = value where conditions</Item>
      <Item>insert into () values()|插入数据,示例insert into TableName(column1, column2) values (value1,value2)</Item>
      <Item>delete from|删除数据,示例delete from TableName where conditions</Item>
      <Item>where|条件子句,示例select column1, column2 from TableName where conditions</Item>
      <Item>group by|分组子句,示例select column1, column2 from TableName group by column1</Item>
      <Item>in ()|判断是否在列表中,示例Item in (1, 2, 3)</Item>
      <Item>like|判断是否类似,示例Item like '%filters%'</Item>
      <Item>order by|顺排序子句,示例select column1, column2 from TableName order by column1</Item>
      <Item>order by desc|逆排序子句,示例select column1, column2 from TableName order by column1 desc</Item>
      <Item>between|判断是否在两者闭区间之间,示例between 1 and 10</Item>
      <Item>is null|判断是否为空,示例Item is null</Item>
      <Item>is not null|判断是否为非空,示例Item is not null</Item>
      <Item>having|支持聚集函数的筛选条件子句,示例select column1, column2 from TableName having conditions</Item>
      <Item>sum()|求和</Item>
      <Item>avg()|求平均</Item>
      <Item>max()|求最大值</Item>
      <Item>min()|求最小值</Item>
      <Item>count()|计数</Item>
      <Item>create table|创建表,示例create table TableName(column1 DataType not null, column2 DataType)</Item>
      <Item>drop table|删除列,示例drop table TableName</Item>
      <Item>alter table add|增加列,示例alter table TableName add ColumnName DataType</Item>
      <Item>alter table drop|删除列,示例alter table TableName drop ColumnName</Item>
      <Item>create index|建立索引,示例create index IndexName on TableName (Column1, Column2)</Item>
      <Item>drop index|建立索引,示例drop index IndexName on TableName, drop index TableName.IndexName</Item>
      <Item>create view|创建视图,示例create view ViewName (column1,column2, ...) as SelectStatement</Item>
      <Item>drop view|删除视图,示例drop view ViewName</Item>
      <Item>create procedure|创建存储过程,示例create procedure ProcedureName (Param1, Param2, ...) as SQLStatement</Item>
      <Item>drop procedure|删除存储过程,示例drop procedure ProcedureName</Item>
      <Item>create trigger|创建触发器,示例create trigger TriggerName on TableName {for insert, update, delete} as SQLStatement</Item>
      <Item>drop trigger|删除触发器,示例drop trigger TriggerName</Item>
   </SQL>
   <函数>
      <Item>abs()|返回表达式的绝对值,示例abs(-1)</Item>
      <Item>acos()|返回已指定余弦的角(以弧度表示),示例acos(0.52)</Item>
      <Item>ascii()|返回表达式中第一个字符的ASCII代码,示例ascii('abc')</Item>
      <Item>asin()|返回已指定正弦的角(以弧度表示),示例asin(0.52)</Item>
      <Item>atan()|返回已指定正切的角(以弧度表示),示例atan(0.50)</Item>
      <Item>cos()|返回指定角的余弦,示例cos(44)</Item>
      <Item>exp()|返回对常数e求指定次幂所得的值,示例exp(3)</Item>
      <Item>floor()|返回小于或等于指定值的最大整数,示例floor(123)</Item>
      <Item>ltrim()|返回删去前导空格的指定表达式,示例ltrim('  123')</Item>
      <Item>power()|返回求指定数据的给定次幂所得的值,示例power(2,3)</Item>
      <Item>rtrim()|返回删去尾随空格的指定表达式,示例rtrim('123  ')</Item>
      <Item>sin()|返回指定角(以弧度表示)的正弦,示例sin(45)</Item>
      <Item>sqrt()|返回指定数字的平方根,示例sqrt(4)</Item>
      <Item>tan()|返回指定角(以弧度表示)的正切,示例tan(60)</Item>
   </函数>
   <筛选>
      <Item>Upper()|把小写字母转换为大写,示例Upper(Item) = 'ALWAYS'</Item>
      <Item>Lower()|把大写字母转换为小写,示例Lower(Item) = 'always'</Item>
      <Item>SubString(,,)|取字符串的子串,示例SubString(DateString, 1, 3) = 'JAN'</Item>
      <Item>Trim()|删除字符串左右空格或指定字符,示例Trim(Item), Trim(Item, '-')</Item>
      <Item>TrimLeft()|删除字符串左边空格或指定字符,示例TrimLeft(Item)</Item>
      <Item>TrimRight()|删除字符串右边空格或指定字符,示例TrimRight(Item)</Item>
      <Item>Year()|取年,返回指定参数的年部份,示例Year(DateField) = 2003</Item>
      <Item>Month()|取月,返回指定参数的月部份,示例Month(DateField) = 12</Item>
      <Item>Day()|取天,返回指定参数的日部份,示例Day(DateField) = 1</Item>
      <Item>Hour()|取小时,返回指定参数的小时部份,示例Hour(DateField) = 16</Item>
      <Item>Minute()|取分钟,返回指定参数的分钟部份,示例Minute(DateField) = 0</Item>
      <Item>Second()|取秒,返回指定参数的秒部份,示例Second(DateField) = 30</Item>
      <Item>GetDate|返回当前日期和时间,示例GetDate - DateField > 7</Item>
      <Item>Date()|取日期,返回指定参数的日期部份,示例DateField = Date(GetDate)</Item>
      <Item>Time()|取时间,返回指定参数的时间部份,示例TimeField > Time(GetDate)</Item>
   </筛选>
</Express>