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#Null
null和undefined的区别
null和undefined都是js中的特殊值,表示缺失或未定义的值。null表示一个空对象指针,即该变量本应该指向一个对象,但是现在没有指向任何一个对象。例如:varobj=null;undefined表示一个未定义的值,即该变量没有被赋值或者被赋值为undefined。例如:varx;console.log(x);...
开发笔记
·
2024-07-02
null
undefined
区别
nullable是什么意思
nullable是一个概念,它指的是可以被设置为null的值。它可以用来表示一个变量或者一个属性的值不存在,或者说这个值本身就是null。在编程语言中,nullable通常用于表示一个变量或者属性的值不存在,或者说这个值本身就是null。例如,在Java中,你可以使用“?”来声明一个变量是nul...
开发笔记
·
2023-12-02
nullable
是什么
意思
ORA-38471: ROWIDs for table aliases cannot be null
文档解释ORA-38471:ROWIDsfortablealiasescannotbenullCause:Anattemptwasmadetopassanullvalueforthetablealiasattributeinthedataitem,whichisnotpermitted.Action:Passavali...
IT技术学习
·
2023-07-28
ORA-38471
ROWIDs
for
table
aliases
ORA-32150: Cannot perform operation on a null timestamp
文档解释ORA-32150:CannotperformoperationonanulltimestampCause:Thetimestampinvolvedinthisoperationisnull.Action:Usevalid,non-nulltimestampinstancetoperformthisoperat...
IT技术学习
·
2023-07-28
ORA-32150
Cannot
perform
operation
on
ORA-25127: RELY not allowed in NOT NULL constraint
文档解释ORA-25127:RELYnotallowedinNOTNULLconstraintCause:AnattempttosetRELYonforNOTNULLconstraint.Action:onlyNORELYmaybespecifiedforaNOTNULLconstraint.ORA-25127是一个O...
IT技术学习
·
2023-07-28
ORA-25127
RELY
not
allowed
in
ORA-30625: method dispatch on NULL SELF argument is disallowed
文档解释ORA-30625:methoddispatchonNULLSELFargumentisdisallowedCause:AmembermethodofatypeisbeinginvokedwithaNULLSELFargument.Action:Changethemethodinvocationtopassin...
IT技术学习
·
2023-07-28
ORA-30625
method
dispatch
on
NULL
ORA-48474: Syntax error specifying product, must not be NULL
文档解释ORA-48474:Syntaxerrorspecifyingproduct,mustnotbeNULLCause:Theproductclauseisbeingused,butnoproductnameisprovidedAction:SupplytheproductnameORA-48474是一个表示系统无...
IT技术学习
·
2023-07-28
ORA-48474
Syntax
error
specifying
product
ORA-22957: NULL is an invalid input to powermultiset and COLLECT functions
文档解释ORA-22957:NULLisaninvalidinputtopowermultisetandCOLLECTfunctionsCause:NULLwasgivenasinputtothepowermultisetorCOLLECTfunction.Action:Giveanon-nullvalueasinpu...
IT技术学习
·
2023-07-28
ORA-22957
NULL
is
an
invalid
ORA-23430: argument “string” cannot be NULL or empty string
文档解释ORA-23430:argument“string”cannotbeNULLoremptystringCause:ThecallerhasprovidedanargumentwhosevaluecannotbeNULLortheemptystring.Action:Checkthatth...
IT技术学习
·
2023-07-28
ORA-23430
argument
#8220string
#8221
cannot
ORA-13910: Parameter string cannot be NULL.
文档解释ORA-13910:ParameterstringcannotbeNULL.Cause:AnattemptwasmadetocallGET_THRESHOLDprocedurewithoutarequiredparameter.Action:Specifyavalidvalueforthisparameter....
IT技术学习
·
2023-07-28
ORA-13910
Parameter
string
cannot
be
ORA-31057: Display Name of the element being inserted is null
文档解释ORA-31057:DisplayNameoftheelementbeinginsertedisnullCause:TheDisplayNameoftheelementwhichisbeinginsertedintotheRESOURCE_VIEWisnullAction:SpecifytheDisplayNa...
IT技术学习
·
2023-07-27
ORA-31057
Display
Name
of
the
ORA-32117: Source LOB is null
文档解释ORA-32117:SourceLOBisnullCause:ThesourceLOBinstanceonwhichtheoperationwasattemptedwasnull.Action:Useavalid,non-nullsourceLOBinstanceforthisoperation.ORA-321...
IT技术学习
·
2023-07-27
ORA-32117
Source
LOB
is
null
ORA-32144: Cannot perform operation on a null interval
文档解释ORA-32144:CannotperformoperationonanullintervalCause:Theintervalinvolvedinthisoperationisnull.Action:Usevalid,non-nullintervalinstancetoperformthisoperation...
IT技术学习
·
2023-07-27
ORA-32144
Cannot
perform
operation
on
ORA-32113: Null object passed
文档解释ORA-32113:NullobjectpassedCause:Nullobjectwaspassed.Action:Passanon-nullobject.ORA-32113:Null对象传递官方解释ORA-32113:null对象传递。一个空引用(Null)对象传递到一个可能使用它的地方。使用null对象类...
IT技术学习
·
2023-07-26
ORA-32113
Null
object
passed
ORA-32114: Cannot perform operation on a null LOB
文档解释ORA-32114:CannotperformoperationonanullLOBCause:TheLOBinstanceonwhichtheoperationwasattemptedwasnull.Action:Useavalid,non-nullLOBinstancetoperformthisoperat...
IT技术学习
·
2023-07-26
ORA-32114
Cannot
perform
operation
on
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