ios – 为什么在将Core Data属性从Integer 16更改为String时会看到此错误？

在尝试更改数据类型时,我得到以下非常长的错误,我该怎么做才能解决它？

2012-07-10 19:33:06.298 MeDicine Tracker[5170:707] Unresolved error Error Domain=NSCocoaErrorDomain Code=134140 "The operation Couldn’t be completed. (Cocoa error 134140.)" UserInfo=0x2ae140 {reason=Can't find or automatically infer mapping model for migration,desTinationModel=(<NsmanagedObjectModel: 0xf694e20>) isEditable 0,entities {
Log = "(<NSEntityDescription: 0xf6947b0>) name Log,managedObjectClassName Log,renamingIdentifier Log,isAbstract 0,superentity name (null),properties {\n    date = \"(<NSAttributeDescription: 0xf6941d0>),name date,isOptional 1,isTransient 0,entity Log,renamingIdentifier date,validation preDicates (\\n),warnings (\\n),versionHashModifier (null)\\n userInfo {\\n},attributeType 900,attributeValueClassName NSDate,DefaultValue (null)\";\n    meDicine = \"(<NSRelationshipDescription: 0xf694410>),name meDicine,renamingIdentifier meDicine,desTination entity MeDicine,inverseRelationship logs,minCount 1,maxCount 1,isordered 0,deleteRule 1\";\n    note = \"(<NSAttributeDescription: 0xf694220>),name note,renamingIdentifier note,attributeType 700,attributeValueClassName NSString,DefaultValue (null)\";\n},subentities (null),userInfo {\n},versionHashModifier (null)";
MeDicine = "(<NSEntityDescription: 0xf694810>) name MeDicine,managedObjectClassName MeDicine,renamingIdentifier MeDicine,properties {\n    active = \"(<NSAttributeDescription: 0xf694270>),name active,entity MeDicine,renamingIdentifier active,attributeType 800,attributeValueClassName NSnumber,DefaultValue (null)\";\n    dose = \"(<NSAttributeDescription: 0xf6942c0>),name dose,renamingIdentifier amount@R_926_10586@ke,DefaultValue (null)\";\n    hoursbetween = \"(<NSAttributeDescription: 0xf694310>),name hoursbetween,renamingIdentifier hoursbetween,attributeType 100,DefaultValue 0\";\n    logs = \"(<NSRelationshipDescription: 0xf694470>),name logs,renamingIdentifier logs,desTination entity Log,inverseRelationship meDicine,minCount 0,maxCount 0,deleteRule 1\";\n    name = \"(<NSAttributeDescription: 0xf694360>),name name,renamingIdentifier name,versionHashModifier (null)\\n userInfo {\\n    \\\"com.apple.syncservices.Syncable\\\" = NO;\\n},userInfo {\n    \"com.apple.syncservices.Syncable\" = NO;\n},versionHashModifier (null)"; },fetch request templates { },sourceModel=(<NsmanagedObjectModel: 0x2adbb0>) isEditable 1,entities {
Log = "(<NSEntityDescription: 0x2ac700>) name Log,properties {\n    date = \"(<NSAttributeDescription: 0x294ac0>),DefaultValue (null)\";\n    meDicine = \"(<NSRelationshipDescription: 0x294a60>),deleteRule 1\";\n    note = \"(<NSAttributeDescription: 0x2ac810>),subentities {\n},versionHashModifier (null)";
MeDicine = "(<NSEntityDescription: 0x294b10>) name MeDicine,properties {\n    active = \"(<NSAttributeDescription: 0x2adaa0>),DefaultValue (null)\";\n    dose = \"(<NSAttributeDescription: 0x2adaf0>),DefaultValue 0\";\n    hoursbetween = \"(<NSAttributeDescription: 0x2adb40>),DefaultValue 0\";\n    logs = \"(<NSRelationshipDescription: 0x2ada40>),deleteRule 1\";\n    name = \"(<NSAttributeDescription: 0x2ad9f0>),NSUnderlyingError=0x2b0140 "The operation Couldn’t be completed. (Cocoa error 134190.)"},{
NSUnderlyingError = "Error Domain=NSCocoaErrorDomain Code=134190 \"The operation Couldn\U2019t be completed. (Cocoa error 134190.)\" UserInfo=0x2b0160 {reason=source and desTination attribute types are incompatible,entity=MeDicine,property=dosE}";
desTinationModel = "(<NsmanagedObjectModel: 0xf694e20>) isEditable 0,entities {\n    Log = \"(<NSEntityDescription: 0xf6947b0>) name Log,properties {\\n    date = \\\"(<NSAttributeDescription: 0xf6941d0>),validation preDicates (\\\\n),warnings (\\\\n),versionHashModifier (null)\\\\n userInfo {\\\\n},DefaultValue (null)\\\";\\n    meDicine = \\\"(<NSRelationshipDescription: 0xf694410>),deleteRule 1\\\";\\n    note = \\\"(<NSAttributeDescription: 0xf694220>),DefaultValue (null)\\\";\\n},userInfo {\\n},versionHashModifier (null)\";\n    MeDicine = \"(<NSEntityDescription: 0xf694810>) name MeDicine,properties {\\n    active = \\\"(<NSAttributeDescription: 0xf694270>),DefaultValue (null)\\\";\\n    dose = \\\"(<NSAttributeDescription: 0xf6942c0>),DefaultValue (null)\\\";\\n    hoursbetween = \\\"(<NSAttributeDescription: 0xf694310>),DefaultValue 0\\\";\\n    logs = \\\"(<NSRelationshipDescription: 0xf694470>),deleteRule 1\\\";\\n    name = \\\"(<NSAttributeDescription: 0xf694360>),versionHashModifier (null)\\\\n userInfo {\\\\n    \\\\\\\"com.apple.syncservices.Syncable\\\\\\\" = NO;\\\\n},userInfo {\\n    \\\"com.apple.syncservices.Syncable\\\" = NO;\\n},versionHashModifier (null)\";\n},fetch request templates {\n}";
reason = "Can't find or automatically infer mapping model for migration";
sourceModel = "(<NsmanagedObjectModel: 0x2adbb0>) isEditable 1,entities {\n    Log = \"(<NSEntityDescription: 0x2ac700>) name Log,properties {\\n    date = \\\"(<NSAttributeDescription: 0x294ac0>),DefaultValue (null)\\\";\\n    meDicine = \\\"(<NSRelationshipDescription: 0x294a60>),deleteRule 1\\\";\\n    note = \\\"(<NSAttributeDescription: 0x2ac810>),subentities {\\n},versionHashModifier (null)\";\n    MeDicine = \"(<NSEntityDescription: 0x294b10>) name MeDicine,properties {\\n    active = \\\"(<NSAttributeDescription: 0x2adaa0>),DefaultValue (null)\\\";\\n    dose = \\\"(<NSAttributeDescription: 0x2adaf0>),DefaultValue 0\\\";\\n    hoursbetween = \\\"(<NSAttributeDescription: 0x2adb40>),DefaultValue 0\\\";\\n    logs = \\\"(<NSRelationshipDescription: 0x2ada40>),deleteRule 1\\\";\\n    name = \\\"(<NSAttributeDescription: 0x2ad9f0>),fetch request templates {\n}"; }