SELECT R1.readerid,R1.readername,R1.unit,R1.bookcount
FROM ReaderInfo AS R1,ReaderInfo AS R2
WHERE R2.readerid=9704
AND R1.bookcount>R2.bookcount     --連接關(guān)系
ORDER BY R1.bookcount

SELECT teacher.*,student.* 
FROM teacher  
  INNER JOIN student 
     ON teacher.id=student.tea_id

/* SELECT statement built using a subquery. */
SELECT Name
FROM AdventureWorks2008R2.Production.Product
WHERE ListPrice =
    (SELECT ListPrice
     FROM AdventureWorks2008R2.Production.Product
     WHERE Name = 'Chainring Bolts' );

/* SELECT statement built using a join that returns
   the same result set. */
SELECT Prd1. Name
FROM AdventureWorks2008R2.Production.Product AS Prd1
     JOIN AdventureWorks2008R2.Production.Product AS Prd2
       ON (Prd1.ListPrice = Prd2.ListPrice)
WHERE Prd2. Name = 'Chainring Bolts';

INSERT INTO MySalesReason
    SELECT SalesReasonID, Name, ModifiedDate
    FROM AdventureWorks2008R2.Sales.SalesReason
    WHERE ReasonType = N'Marketing';

SELECT SalesOrderID, SUM(LineTotal) AS SubTotal
FROM Sales.SalesOrderDetail
GROUP BY SalesOrderID
HAVING SUM(LineTotal) > 100000.00
ORDER BY SalesOrderID ;

  public System.String UserName
        {
            get { return getProperty<System.String>("UserName"); }
            set { setProperty("UserName", value, 50); }
        }

          /// <summary>
        /// 獲取屬性值
        /// </summary>
        /// <typeparam name="T">值的類型</typeparam>
        /// <param name="propertyName">屬性名稱</param>
        /// <returns>屬性值</returns>
        protected T getProperty<T>(string propertyName)
        {
            this.OnPropertyGeting(propertyName);
            return CommonUtil.ChangeType<T>(PropertyList(propertyName));
        }

        /// <summary>
        /// 屬性獲取事件
        /// </summary>
        public event EventHandler<PropertyGettingEventArgs> PropertyGetting;
        /// <summary>
        /// 獲取屬性的時(shí)候
        /// </summary>
        /// <param name="name"></param>
        protected virtual void OnPropertyGeting(string name)
        {
            if (this.PropertyGetting != null)
            {
                this.PropertyGetting(this, new PropertyGettingEventArgs(name));
            }
        }

 public OQL(EntityBase e)
        {
            currEntity = e;
           //其它代碼略
            e.PropertyGetting += new EventHandler<PropertyGettingEventArgs>(e_PropertyGetting);
        }

void e_PropertyGetting(object sender, PropertyGettingEventArgs e)
        {
            //其它代碼略
         }

Users user = new Users();
OQL q0 = OQL.From(user)
            .Select(user.ID, user.UserName, user.RoleID）
              .END;

SELECT
     [ID],
     [UserName],
     [RoleID]
FROM [LT_Users]

        void e_PropertyGetting(object sender, PropertyGettingEventArgs e)
        {
            doPropertyGetting(((EntityBase)sender).TableName, e.PropertyName);
        }

        private void doPropertyGetting(string tableName, string propertyName)
        {
            if (isJoinOpt)
            {
                string propName = "[" + tableName + "].[" + propertyName + "]";
                this.currJoinEntity.AddJoinFieldName(propName);

            }
            else
            {
                string field = this.joinedString.Length > 0 ? tableName + "].[" + propertyName : propertyName;
                if (!hasSelected && !selectedFields.Contains(field))
                    selectedFields.Add(field);
            }
            this.getingTableName = tableName;
            this.getingPropertyName = propertyName;
        }

      void e_PropertyGetting(object sender, PropertyGettingEventArgs e)
        {
            TableNameField tnf = new TableNameField()
            {
                Field = e.PropertyName,
                Entity = (EntityBase)sender,
                Index=this.GetFieldGettingIndex()
            };

            fieldStack.Push(tnf);
        }

        /// <summary>
        /// 使用一個(gè)實(shí)體對(duì)象初始化本類
        /// </summary>
        /// <param name="e"></param>
        public OQLCompare(EntityBase e)
        {
            this.CurrEntity = e;
            //this.CurrEntity.ToCompareFields = true;
            this.CurrEntity.PropertyGetting += new EventHandler<PropertyGettingEventArgs>(CurrEntity_PropertyGetting);
        }

        /// <summary>
        /// 使用多個(gè)實(shí)體類進(jìn)行連接查詢的條件
        /// </summary>
        /// <param name="e"></param>
        /// <param name="joinedEntitys"></param>
        public OQLCompare(EntityBase e, params EntityBase[] joinedEntitys)
        {
            this.CurrEntity = e;
            this.CurrEntity.PropertyGetting += new EventHandler<PropertyGettingEventArgs>(CurrEntity_PropertyGetting);
            //處理多個(gè)實(shí)體類
            if (joinedEntitys != null && joinedEntitys.Length > 0)
            {
                this.joinedEntityList = new List<EntityBase>();
                foreach (EntityBase item in joinedEntitys)
                {
                    this.joinedEntityList.Add(item);
                    item.PropertyGetting += new EventHandler<PropertyGettingEventArgs>(CurrEntity_PropertyGetting);
                }
            }

        }

        void CurrEntity_PropertyGetting(object sender, PropertyGettingEventArgs e)
        {
            if (this.joinedEntityList != null)
            {
                this.currPropName = "[" + ((EntityBase)sender).TableName + "].[" + e.PropertyName + "]";
            }
            else
            {
                this.currPropName = "[" + e.PropertyName + "]";
                //propertyList.Add(e.PropertyName);
            }

        }

       /// <summary>
        /// 從堆棧上只取一個(gè)字段名
        /// </summary>
        /// <returns></returns>
        protected internal string TakeOneStackFields()
        {
           //其它代碼略
              TableNameField tnf = fieldStack.Pop();
            return GetOqlFieldName(tnf);
        }

SELECT Field1,Field2...    FROM [Table]

-----------------

SELECT Field1,Field2...    FROM [Table]
    WHERE Condition

-----------------

SELECT Field1,Field2...    FROM [Table]
    WHERE Condition
        ORDER BY FieldOrder 

-----------------

SELECT FieldGroup    FROM [Table]
    WHERE Condition
        GROUP BY FieldGroup
            ORDER BY FieldOrder 

----------------

SELECT FieldGroup    FROM [Table]
    WHERE Condition
        GROUP BY FieldGroup
            HAVING havingExp
                ORDER BY FieldOrder 

-----------------

SELECT Field1,Field2...    FROM [Table1]
JOIN [Table2] ON [Table1].PK=[Table2].FK
    WHERE Condition
        ORDER BY FieldOrder 

-----------------

SELECT Field1,Field2...    FROM [Table1],[Table2]
     WHERE [Table1].PK=[Table2].FK And OtherCondition
        ORDER BY FieldOrder 

-----------------

SELECT FROM
    JOIN ON
    WHERE
        GROUP BY
            HAVEING
                ORDER BY

public interface IOQL
    {
        OQL1 Select(params object[] fields);
    }

    public interface IOQL1 : IOQL2
    {
        //OQL End { get; }
        //OQL3 GroupBy(object field);
        //OQL4 Having(object field);
        //OQL4 OrderBy(object field);
        OQL2 Where(params object[] fields);
    }

    public interface IOQL2 : IOQL3
    {
        //OQL End { get; }
        OQL3 GroupBy(object field);
        //OQL4 Having(object field);
        //OQL4 OrderBy(object field);
    }

    public interface IOQL3 : IOQL4
    {
        OQL4 Having(object field);
        //OQL End { get; }
        //OQL4 OrderBy(object field);
    }

    public interface IOQL4
    {
        OQL END { get; }
        OQLOrderType OrderBy(object field);
    }

SELECT  M.*,T0.*  
FROM [LT_Users]  M  
INNER JOIN [LT_UserRoles] T0  ON  M.[RoleID] = T0.[ID] 
     WHERE 
    (   M.[UserName] = @P0 AND  M.[Password] = @P1  AND  T0.[RoleName] = @P2 )
 OR 
    (
      (
         M.[UserName] = @P3 AND  M.[Password] = @P4  AND  T0.[ID]  IN  (1,2,3) 
      ) 
    OR 
     M.[LastLoginTime] > @P5 )

public class OQLCompare
{

//其它代碼略

        protected OQLCompare LeftNode { get; set; }

        protected OQLCompare RightNode { get; set; }

        protected CompareLogic Logic { get; set; }

        protected bool IsLeaf
        {
            get
            {
                return object.Equals(LeftNode, null) && object.Equals(RightNode, null);
            }
        }

        protected string ComparedFieldName;
        protected string ComparedParameterName;
        protected CompareType ComparedType;

}

SELECT  M.*,T0.*  
FROM [LT_Users]  M  
INNER JOIN [LT_UserRoles] T0  ON  M.[RoleID] = T0.[ID] 
     WHERE 
    ((  ( M.[UserName] = @P0 AND  M.[Password] = @P1)  AND  T0.[RoleName] = @P2 )
 OR 
    (
      (
         (M.[UserName] = @P3 AND  M.[Password] = @P4)  AND  T0.[ID]  IN  (1,2,3) 
      ) 
    OR 
     M.[LastLoginTime] > @P5 ) )

• (A AND B) AND C <==> A AND B AND C
  • (A OR B) OR C <==> A OR B OR C
    • (A AND B) AND (C AND D) <==> A AND B AND C AND D
      • (A OR B) OR (C OR D) <==> A OR B OR C OR D