有话说之前我写了3篇关于表达式树解析的文章
干货!表达式树解析"框架"(1)
干货!表达式树解析"框架"(2)
干货!表达式树解析"框架"(3)
这3篇文章更多的是说明一种方法,一种思路,而代码比较少
在发出来之后也有些朋友互加了好友一起讨论
在经过一些时间的修改和优化后,就有了现在这个框架
目前这个框架实现了SqlServer和Oracle的解释
其他数据库1来是不熟2来没时间3来我更希望大家可以使用这个框架自己动手实现一个数据库的解析,非常有意思
特色首先是这个框架的名字 : Faller 中译 伐木工,但我喜欢叫他 "砍树人",因为他把"表达式树"这颗大树砍成一片一片的小块然后转化成sql语句轻量 : 不仅仅是代码轻量,重新实现对一个新的数据库支持也很轻量,只需要实现ISaw接口,或继承BaseSaw实现少量方法即可
如 :
Where(u => u.Birthday.Day ==1);//EXTRACT(DAY FROM a.BIRTHDAY) = 1Where(u => u.Name.Trim() =="");//ltrim(rtrim(a.NAME)) = :auto_p0Where(u =>string.IsNullOrEmpty(u.Name));//a.NAME IS NULL OR a.NAME == ''
灵活 : 在轻量的基础上尽量做到了灵活,可以非常方便的解析各种C#的方法
对 DateTime.Now 的处理 :
如 : Where(u => u.Birthday < DateTime.Now)//可以被解析为 BIRTHDAY < SYSDATE 或 BIRTHDAY < GETDATE() 自由的 SqlExPR: 有时候 我们不得不使用Sql来表示某个数据库特有的数据
如 : Set<User>(() =>newUser{ ID = (SqlExpr)"seq_user.nextval"})//解析后得到 ID = seq_user.nextval 使用方便 : 可以非常方便的嵌入到现已有的项目中,主要根据自己项目的需求重新实现ISaw即可
使用方式voidWhere(stringexpected, Expression<Func<User,bool>>expr)
{varparse =Faller.Create(expr);//通过LambdaExpression创建Faller对象varsql = parse.ToWhere(OracleSaw.Instance);//使用特定的ISaw来格式化Sql语句//parse.Parameters//解析过程中产生的参数Assert.AreEqual(expected, sql);
}
项目结构Faller: 解析框架主要功能类,不可重写,实现 IFaller 接口,主要方法有 publicstaticIFallerCreate(LambdaExpressionexpr)ISaw: 定义一组方法，它支持自定义Sql语句的格式。Faller负责拆解 LambdaExpression ,然后把特定的对象交给ISaw处理返回sql语句 SawDust: 解析结果。当一个方法在Faller中无法被解释时候,Faller会把方法所用到的对象和参数都构造成为SawDust 并交给ISaw处理,SawDust 由DustType Type和Object Value组成DustType: 表示解释结果类型的枚举 ,它的值有 Undefined, Sql, Object, Number, Array, Boolean, DateTime, Binary, StringSqlExpr: Sql表达式,它只能由String强转获得; 它可以隐式转换为所有基础对象,但只能在表达式树中使用, 如
Where<User>(u => (SqlExpr)"@@identity"==5);//@@identity = 5
对象定义//轻量级表达式树解析器 接口publicinterfaceIFaller
{//将表达式转为Where语句,不包含Where关键字//saw: 自定义输出Sql语句的格式的对象stringToWhere(ISaw saw);//将表达式转为OrderBy语句,不包含OrderBy关键字//saw: 自定义输出Sql语句的格式的对象//asc: 正序或倒序标识stringToOrderBy(ISaw saw,boolasc);//将表达式转为Update中Set语句,不包含Set关键字//saw: 自定义输出Sql语句的格式的对象stringToSets(ISaw saw);//将表达式转为select语句中的列或列集合的Sql语句//saw: 自定义输出Sql语句的格式的对象stringToSelectColumns(ISaw saw);//将表达式转为值或值集合的sql语句//saw: 自定义输出Sql语句的格式的对象stringToValues(ISaw saw);//将表达式转为值或值集合的sql语句//saw: 自定义输出Sql语句的格式的对象stringToValues(ISaw saw, Func<string,string>replace);//将表达式转为列集合和值集合2个sql语句,可用于拼装insert语句//saw: 自定义输出Sql语句的格式的对象KeyValuePair<string,string>ToColumnsAndValues(ISaw saw);//转换Sql语句过程中产生的参数ICollection<DbParameter> Parameters {get; }
}
IFaller
///<summary>定义一组方法，它支持自定义Sql语句的格式。///</summary>publicinterfaceISaw
{///<summary>解释二元操作///</summary>///<param name="left">左元素</param>///<param name="Operator">二元操作符</param>///<param name="right">右元素</param>stringBinaryOperation(stringleft, BinaryOperator @operator,stringright);///<summary>解释Contains操作///</summary>///<param name="not">是否为not</param>///<param name="item">要在集合中查找的对象</param>///<param name="array">要查找的集合</param>stringContainsOperation(boolnot,stringitem,string[] array);///<summary>向参数集合中追加一个任意类型的参数,并返回参数名sql表达式///</summary>///<param name="obj">需要追加的参数值</param>///<param name="parameters">参数集合</param>stringAddObject(objectobj, ICollection<DbParameter>parameters);///<summary>向参数集合中追加一个数字类型的参数,并返回参数名sql表达式///</summary>///<param name="number">需要追加的数字</param>///<param name="parameters">参数集合</param>stringAddNumber(IConvertible number, ICollection<DbParameter>parameters);///<summary>向参数集合中追加一个布尔类型的参数,并返回参数名sql表达式///</summary>///<param name="obj">需要追加的布尔值</param>///<param name="parameters">参数集合</param>stringAddBoolean(boolvalue, ICollection<DbParameter>parameters);///<summary>向参数集合中追加当前时间,并返回参数名sql表达式///</summary>///<param name="parameters">参数集合</param>stringAddTimeNow(ICollection<DbParameter>parameters);///<summary>获取实体类型所映射的表名///</summary>///<param name="type">实体类型</param>///<param name="alias">别名</param>stringGetTable(Type type,stringalias);///<summary>获取实体属性或字段所映射的列名///</summary>///<param name="table">表名或表别名</param>///<param name="type">实体属性或字段</param>stringGetColumn(stringtable, MemberInfo member);///<summary>获取列名和列别名组合后的sql表达式///</summary>///<param name="columnName">列名</param>///<param name="alias">列别名</param>stringGetColumn(stringcolumnName,stringalias);///<summary>将.NET中的方法解释为sql表达式///</summary>///<param name="method">需解释的方法</param>///<param name="target">方法调用者</param>///<param name="args">方法参数</param>///<returns></returns>stringParseMethod(MethodInfo method, SawDust target, SawDust[] args);
}
ISaw
///<summary>表达式树解析结果///</summary>publicstructSawDust
{///<summary>结果类型///</summary>publicreadonlyDustType Type;///<summary>结果值///</summary>publicreadonlyObject Value;///<summary>无论结果类型 强制转换为Sql语句,DustType.Undefined抛出异常///</summary>publicstringToSql();///<summary>是否是非DustType.Sql和DustType.Undefined类型///</summary>publicboolIsObject {get;}
}
SawDust(不包含实现)
///<summary>表达式解析结果类型///</summary>[System.Serializable]publicenumDustType
{///<summary>未知///</summary>Undefined =0,///<summary>sql语句///</summary>Sql =1,///<summary>未知类型///</summary>Object =2,///<summary>数字///</summary>Number =3,///<summary>数组///</summary>Array =4,///<summary>布尔值///</summary>Boolean =5,///<summary>时间///</summary>DateTime =6,///<summary>二进制///</summary>Binary =7,///<summary>字符串///</summary>String =8,
}
DustType
///<summary>Sql表达式///</summary>publicstructSqlExpr
{publicstaticexplicitoperatorSqlExpr(stringvalue);publicstaticimplicitoperatorbool(SqlExpr value);publicstaticimplicitoperatorbyte(SqlExpr value);publicstaticimplicitoperatorchar(SqlExpr value);publicstaticimplicitoperatorDateTime(SqlExpr value);publicstaticimplicitoperatordecimal(SqlExpr value);publicstaticimplicitoperatordouble(SqlExpr value);publicstaticimplicitoperatorshort(SqlExpr value);publicstaticimplicitoperatorint(SqlExpr value);publicstaticimplicitoperatorlong(SqlExpr value);publicstaticimplicitoperatorsbyte(SqlExpr value);publicstaticimplicitoperatorfloat(SqlExpr value);publicstaticimplicitoperatorstring(SqlExpr value);publicstaticimplicitoperatorushort(SqlExpr value);publicstaticimplicitoperatoruint(SqlExpr value);publicstaticimplicitoperatorulong(SqlExpr value);publicstaticimplicitoperatorGuid(SqlExpr value);publicstaticimplicitoperatorByte[](SqlExpr value);
}
SqlExpr
///<summary>支持自定义Sql语句格式基类。///</summary>publicabstractclassBaseSaw : ISaw
{///<summary>初始化并提供 DbProviderFactory///</summary>///<param name="factory"></param>protectedBaseSaw(DbProviderFactory factory);/** 接口已定义方法略...*////<summary>解释未知的方法///</summary>///<param name="method">需解释的方法</param>///<param name="target">方法调用者</param>///<param name="args">方法参数</param>protectedvirtualstringParseUnknownMethod(MethodInfo method, SawDust target, SawDust[] args);///<summary>获取新的数据库参数///</summary>///<param name="obj">参数值</param>protectedvirtualDbParameter GetDbParameter(objectobj);///<summary>别名分隔符 默认 AS ,如 Table AS it///</summary>protectedvirtualstringAliasSeparator {get; }///<summary>解释按位运算 与,或,非///</summary>///<param name="val1">操作数1</param>///<param name="val2">操作数2</param>///<param name="opt">按位操作符</param>protectedvirtualstringBitOperation(stringval1,stringval2, BitOperator opt);///<summary>解释取余运算///</summary>///<param name="val1">操作数1</param>///<param name="val2">操作数2</param>///<returns></returns>protectedvirtualstringModuloOperation(stringval1,stringval2);///<summary>解释幂运算///</summary>///<param name="val1">操作数1</param>///<param name="val2">操作数2</param>///<returns></returns>protectedvirtualstringPowerOperation(stringval1,stringval2);///<summary>解释位移运算///</summary>///<param name="val1">操作数1</param>///<param name="val2">操作数2</param>///<param name="opt">按位操作符</param>protectedvirtualstringShiftOperation(stringval1,stringval2, ShiftOperator opt);///<summary>解释 String.Trim 方法///</summary>///<param name="target">方法调用者</param>///<param name="arg">方法参数</param>protectedvirtualstringStringTrim(stringtarget,stringarg);///<summary>解释 String.TrimEnd 方法///</summary>///<param name="target">方法调用者</param>///<param name="arg">方法参数</param>protectedvirtualstringStringTrimEnd(stringtarget,stringarg);///<summary>解释 String.TrimStart 方法///</summary>///<param name="target">方法调用者</param>///<param name="arg">方法参数</param>protectedvirtualstringStringTrimStart(stringtarget,stringarg);///<summary>解释 String.IsNullOrEmpty 方法///</summary>///<param name="target">方法调用者</param>protectedvirtualstringStringIsNullOrEmpty(stringtarget);///<summary>解释 String.IsNullOrWhiteSpace 方法///</summary>///<param name="target">方法调用者</param>protectedvirtualstringStringIsNullOrWhiteSpace(stringtarget);///<summary>解释 String.Length 方法///</summary>///<param name="target">方法调用者</param>protectedvirtualstringStringLength(stringtarget);///<summary>解释 Object.ToString 方法///</summary>///<param name="type">调用者类型</param>///<param name="target">方法调用者</param>///<param name="format">格式化参数</param>protectedvirtualstringObjectToString(DustType type,stringtarget,stringformat);///<summary>解释 DateTime 中的数据///</summary>///<param name="datetime">方法调用者</param>protectedvirtualstringDateTimeToField(stringdatetime, DateTimeField field);///<summary>解释各种 Number.Parse 方法///</summary>///<param name="target">string对象</param>protectedvirtualstringSrtingToNumber(stringtarget);#regionabstract///<summary>返回实体类型所映射的表名///</summary>///<param name="type">实体类型</param>protectedabstractstringTableName(Type type);///<summary>返回实体属性或字段所映射的列名///</summary>///<param name="member">实体属性或字段</param>protectedabstractstringColumnName(MemberInfo member);///<summary>参数的前缀符号,如SqlServer中的@,Oracle中的:///</summary>protectedabstractstringParameterPreFix {get; }///<summary>在数据库中表示当前时间的表达式,如SqlServer中的getdate,Oracle中的SYSDATE///</summary>protectedabstractstringTimeNow {get; }///<summary>解释Like操作///</summary>///<param name="val1">操作数1</param>///<param name="val2">操作数2</param>///<param name="opt">按位操作符</param>protectedabstractstringLikeOperation(stringval1,stringval2, LikeOperator opt);#endregion}
BaseSaw(不包含实现)
///<summary>二元操作符枚举///</summary>[Serializable]publicenumBinaryOperator
{///<summary>加///</summary>Add,///<summary>减///</summary>Subtract,///<summary>除///</summary>Divide,///<summary>取余///</summary>Modulo,///<summary>乘///</summary>Multiply,///<summary>幂运算///</summary>Power,///<summary>位移运算 a << b///</summary>LeftShift,///<summary>位移运算 a >> b///</summary>RightShift,///<summary>与 a && b 或 a AND b///</summary>And,///<summary>或 a || b 或 a OR b///</summary>Or,///<summary>等于 a == b///</summary>Equal,///<summary>不等于 a != b 或 a<>b///</summary>NotEqual,///<summary>大于 a > b///</summary>GreaterThan,///<summary>大于等于 a >= b///</summary>GreaterThanOrEqual,///<summary>小于 a < b///</summary>LessThan,///<summary>小于等于 a <= b///</summary>LessThanOrEqual,///<summary>LIKE操作 a LIKE %b%///</summary>Contains,///<summary>LIKE操作 a LIKE b%///</summary>StartWith,///<summary>LIKE操作 a LIKE %b///</summary>EndWith,///<summary>LIKE操作 a NOT LIKE %b%///</summary>NotContains,///<summary>LIKE操作 a NOT LIKE b%///</summary>NotStartWith,///<summary>LIKE操作 a NOT LIKE %b///</summary>NotEndWith,///<summary>位运算 如 a & b///</summary>BitAnd,///<summary>位运算 如 a | b///</summary>BitOr,///<summary>位运算 如 a ^ b///</summary>BitXor,
}///<summary>按位操作符枚举///</summary>[Serializable]publicenumBitOperator
{///<summary>位运算 如 a & b///</summary>And,///<summary>位运算 如 a | b///</summary>Or,///<summary>位运算 如 a ^ b///</summary>Xor,
}///<summary>Like操作符枚举///</summary>[Serializable]publicenumLikeOperator
{///<summary>LIKE操作 a LIKE %b%///</summary>Contains,///<summary>LIKE操作 a LIKE b%///</summary>StartWith,///<summary>LIKE操作 a LIKE %b///</summary>EndWith,///<summary>LIKE操作 a NOT LIKE %b%///</summary>NotContains,///<summary>LIKE操作 a NOT LIKE b%///</summary>NotStartWith,///<summary>LIKE操作 a NOT LIKE %b///</summary>NotEndWith,
}///<summary>位移操作符枚举///</summary>[Serializable]publicenumShiftOperator
{///<summary>位移运算 a << b///</summary>Left,///<summary>位移运算 a >> b///</summary>Right,
}///<summary>时间字段///</summary>[Serializable]publicenumDateTimeField
{///<summary>年///</summary>Year,///<summary>月///</summary>Month,///<summary>日///</summary>Day,///<summary>时///</summary>Hour,///<summary>分///</summary>Minute,///<summary>秒///</summary>Second,///<summary>星期///</summary>Week,
}
其他枚举
再来一个已实现的MsSqlSaw
publicclassMsSqlSaw : BaseSaw
{publicstaticMsSqlSaw Instance =newMsSqlSaw();privateMsSqlSaw() :base(System.Data.SqlClient.SqlClientFactory.Instance) { }privatestaticHashSet<string> KeyWords =InitKeyWords();privatestaticHashSet<string>InitKeyWords()
{returnnewHashSet<string>("ABSOLUTE,ACTION,ADA,ADD,ADMIN,AFTER,AGGREGATE,ALIAS,ALL,ALLOCATE,ALTER,AND,ANY,ARE,ARRAY,AS,ASC,ASSERTION,AT,AUTHORIZATION,AVG,BACKUP,BEFORE,BEGIN,BETWEEN,BINARY,BIT,BIT_LENGTH,BLOB,BOOLEAN,BOTH,BREADTH,BREAK,BROWSE,BULK,BY,CALL,CASCADE,CASCADED,CASE,CAST,CATALOG,CHAR,CHARACTER,CHARACTER_LENGTH,CHAR_LENGTH,CHECK,CHECKPOINT,CLASS,CLOB,CLOSE,CLUSTERED,COALESCE,COLLATE,COLLATION,COLUMN,COMMIT,COMPLETION,COMPUTE,CONNECT,CONNECTION,CONSTRAINT,CONSTRAINTS,CONSTRUCTOR,CONTAINS,CONTAINSTABLE,CONTINUE,CONVERT,CORRESPONDING,COUNT,CREATE,CROSS,CUBE,CURRENT,CURRENT_DATE,CURRENT_PATH,CURRENT_ROLE,CURRENT_TIME,CURRENT_TIMESTAMP,CURRENT_USER,CURSOR,CYCLE,DATA,DATABASE,DATE,DAY,DBCC,DEALLOCATE,DEC,DECIMAL,DECLARE,DEFAULT,DEFERRABLE,DEFERRED,DELETE,DENY,DEPTH,DEREF,DESC,DESCRIBE,DESCRIPTOR,DESTROY,DESTRUCTOR,DETERMINISTIC,DIAGNOSTICS,DICTIONARY,DISCONNECT,DISK,DISTINCT,DISTRIBUTED,DOMAIN,DOUBLE,DROP,DUMMY,DUMP,DYNAMIC,EACH,ELSE,END,END-EXEC,EQUALS,ERRLVL,ESCAPE,EVERY,EXCEPT,EXCEPTION,EXEC,EXECUTE,EXISTS,EXIT,EXTERNAL,EXTRACT,FALSE,FETCH,FILE,FILLFACTOR,FIRST,FLASE,FLOAT,FOR,FOREIGN,FORTRAN,FOUND,FREE,FREETEXT,FREETEXTTABLE,FROM,FULL,FUNCTION,GENERAL,GET,GLOBAL,GO,GOTO,GRANT,GROUP,GROUPING,HAVING,HOLDLOCK,HOST,HOUR,IDENTITY,IDENTITYCOL,IDENTITY_INSERT,IF,IGNORE,IMMEDIATE,IN,INCLUDE,INDEX,INDICATOR,INITIALIZE,INITIALLY,INNER,INOUT,INPUT,INSENSITIVE,INSERT,INT,INTEGER,INTERSECT,INTERVAL,INTO,IS,ISOLATION,ITERATE,JOIN,KEY,KILL,LANGUAGE,LARGE,LAST,LATERAL,LEADING,LEFT,LESS,LEVEL,LIKE,LIMIT,LINENO,LOAD,LOCAL,LOCALTIME,LOCALTIMESTAMP,LOCATOR,LOWER,MAP,MATCH,MAX,MIN,MINUTE,MODIFIES,MODIFY,MODULE,MONTH,NAMES,NATIONAL,NATURAL,NCHAR,NCLOB,NEW,NEXT,NO,NOCHECK,NONCLUSTERED,NONE,NOT,NULL,NULLIF,NUMERIC,OBJECT,OCTET_LENGTH,OF,OFF,OFFSETS,OLD,ON,ONLY,OPEN,OPENDATASOURCE,OPENQUERY,OPENROWSET,OPENxml,OPERATION,OPTION,OR,ORDER,ORDINALITY,OUT,OUTER,OUTPUT,OVER,OVERLAPS,PAD,PARAMETER,PARAMETERS,PARTIAL,PASCAL,PATH,PERCENT,PLAN,POSITION,POSTFIX,PRECISION,PREFIX,PREORDER,PREPARE,PRESERVE,PRIMARY,PRINT,PRIOR,PRIVILEGES,PROC,PROCEDURE,PUBLIC,RAISERROR,READ,READS,READTEXT,REAL,RECONFIGURE,RECURSIVE,REF,REFERENCES,REFERENCING,RELATIVE,REPLICATION,RESTORE,RESTRICT,RESULT,RETURN,RETURNS,REVOKE,RIGHT,ROLE,ROLLBACK,ROLLUP,ROUTINE,ROW,ROWCOUNT,ROWGUIDCOL,ROWS,RULE,SAVE,SAVEPOINT,SCHEMA,SCOPE,SCROLL,SEARCH,SECOND,SECTION,SELECT,SEQUENCE,session,SESSION_USER,SET,SETS,SETUSER,SHUTDOWN,SIZE,SMALLINT,SOME,SPACE,SPECIFIC,SPECIFICTYPE,SQL,SQLCA,SQLCODE,SQLERROR,SQLEXCEPTION,SQLSTATE,SQLWARNING,START,STATE,STATEMENT,STATIC,STATISTICS,STRUCTURE,SUBSTRING,SUM,SYSTEM_USER,TABLE,TEMPORARY,TERMINATE,TEXTSIZE,THAN,THEN,TIME,TIMESTAMP,TIMEZONE_HOUR,TIMEZONE_MINUTE,TO,TOP,TRAILING,TRAN,TRANSACTION,TRANSLATE,TRANSLATION,TREAT,TRIGGER,TRIM,TRUE,TRUNCATE,TSEQUAL,UNDER,UNION,UNIQUE,UNKNOWN,UNNEST,UPDATE,UPDATETEXT,UPPER,USAGE,USE,USER,USING,VALUE,VALUES,VARCHAR,VARIABLE,VARYING,VIEW,WAITFOR,WHEN,WHENEVER,WHERE,WHILE,WITH,WITHOUT,WORK,WRITE,WRITETEXT,YEAR,ZONE".Split(','), StringComparer.OrdinalIgnoreCase);
}protectedoverridestringTableName(Type type)
{varname =type.Name;if(KeyWords.Contains(name))
{returnstring.Concat("[", name,"]");
}returnname;
}protectedoverridestringColumnName(MemberInfo member)
{varname =member.Name;if(KeyWords.Contains(name))
{returnstring.Concat("[", name,"]");
}returnname;
}protectedoverridestringParameterPreFix {get{return"@"; } }protectedoverridestringTimeNow {get{return"GETDATE()"; } }protectedoverridestringLikeOperation(stringval1,stringval2, LikeOperator opt)
{switch(opt)
{caseLikeOperator.Contains:returnstring.Concat(val1,"LIKE '%' +", val2,"+ '%'");caseLikeOperator.StartWith:returnstring.Concat(val1,"LIKE", val2,"+ '%'");caseLikeOperator.EndWith:returnstring.Concat(val1,"LIKE '%' +", val2);caseLikeOperator.NotContains:returnstring.Concat(val1,"NOT LIKE '%' +", val2,"+ '%'");caseLikeOperator.NotStartWith:returnstring.Concat(val1,"NOT LIKE", val2,"+ '%'");caseLikeOperator.NotEndWith:returnstring.Concat(val1,"NOT LIKE '%' +", val2);default:thrownewArgumentOutOfRangeException("opt");
}
}protectedoverridestringBitOperation(stringval1,stringval2, BitOperator opt)
{switch(opt)
{caseBitOperator.And:returnstring.Concat(val1,"&", val2);caseBitOperator.Or:returnstring.Concat(val1,"|", val2);caseBitOperator.Xor:returnstring.Concat(val1,"^", val2);default:thrownewArgumentOutOfRangeException("opt");
}
}protectedoverridestringStringTrim(stringtarget,stringarg)
{if(arg !=null)
{thrownewNotSupportedException("不支持参数");
}returnstring.Concat("LTRIM(RTRIM(", target,"))");
}protectedoverridestringStringTrimEnd(stringtarget,stringarg)
{if(arg !=null)
{thrownewNotSupportedException("不支持参数");
}returnstring.Concat("RTRIM(", target,")");
}protectedoverridestringStringTrimStart(stringtarget,stringarg)
{if(arg !=null)
{thrownewNotSupportedException("不支持参数");
}returnstring.Concat("LTRIM(", target,")");
}protectedoverridestringStringLength(stringtarget)
{returnstring.Concat("LEN(", target,")");
}protectedoverridestringSrtingToNumber(stringtarget)
{returnstring.Concat("CAST(", target,"as decimal)");
}protectedoverridestringObjectToString(DustType type,stringtarget,stringformat)
{switch(type)
{caseDustType.Undefined:
break;caseDustType.Sql:
break;caseDustType.Object:
break;caseDustType.Number:if(format !=null)
{thrownewNotSupportedException("不支持参数");
}returnstring.Concat("CAST(", target,"as NVARCHAR)");caseDustType.Array:
break;caseDustType.Boolean:
break;caseDustType.DateTime:switch(format)
{case"'HH:mm'":returnstring.Concat("CONVERT(VARCHAR(5),", target,",114)");case"'HH:mm:ss'":returnstring.Concat("CONVERT(VARCHAR(8),", target,",114)");case"'HH:mm:ss.fff'":returnstring.Concat("CONVERT(VARCHAR(12),", target,",114)");case"'yyyy-MM-dd'":returnstring.Concat("CONVERT(VARCHAR(10),", target,",21)");case"'yyyy-MM-dd HH:mm'":returnstring.Concat("CONVERT(VARCHAR(16),", target,",21)");case"'yyyy-MM-dd HH:mm:ss'":returnstring.Concat("CONVERT(VARCHAR(19),", target,",21)");case"'yyyy-MM-dd HH:mm:ss.fff'":returnstring.Concat("CONVERT(VARCHAR(23),", target,",21)");case"'yy/MM/dd'":returnstring.Concat("CONVERT(VARCHAR(8),", target,",111)");case"'yyMMdd'":returnstring.Concat("CONVERT(VARCHAR(6),", target,",112)");default:
break;
}thrownewNotSupportedException("不支持当前参数");caseDustType.Binary:
break;caseDustType.String:
break;default:
break;
}returnbase.ObjectToString(type, target, format);
}protectedoverridestringDateTimeToField(stringdatetime, DateTimeField field)
{switch(field)
{caseDateTimeField.Year:returnstring.Concat("DATEPART(YYYY,", datetime,")");caseDateTimeField.Month:returnstring.Concat("DATEPART(mm,", datetime,")");caseDateTimeField.Day:returnstring.Concat("DATEPART(dd,", datetime,")");caseDateTimeField.Hour:returnstring.Concat("DATEPART(hh,", datetime,")");caseDateTimeField.Minute:returnstring.Concat("DATEPART(mi,", datetime,")");caseDateTimeField.Second:returnstring.Concat("DATEPART(ss,", datetime,")");caseDateTimeField.Week:returnstring.Concat("(DATEPART(w,", datetime,") - 1)");default:thrownewArgumentOutOfRangeException("field");
}
}
}
MsSqlSaw
部分解释结果展示(以OracleSaw为例)
下载地址https://code.csdn.net/jy02305022/blqw-faller
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