外部支持设置 是否把 null 转为 @""

Author: ljh

LKDBHelper/Helper/LKDBHelper.h

@@ -20,10 +20,15 @@
 @interface LKDBHelper : NSObject
 
 /**
- *  @brief 是否打印数据库出错日志 默认 NO
+ *  @brief Log error message, Default: NO
  */
 + (void)setLogError:(BOOL)logError;
 
+/**
+ *  @brief null is '' , Default: NO
+ */
++ (void)setNullToEmpty:(BOOL)empty;
+
 /**
  *	@brief  filepath the use of : "documents/db/" + fileName + ".db"
  *  refer:  FMDatabase.h  + (instancetype)databaseWithPath:(NSString*)inPath;

LKDBHelper/Helper/LKDBHelper.m

@@ -77,6 +77,15 @@ + (void)setLogError:(BOOL)logError
     }
 #endif
 }
+static BOOL LKDBNullIsEmptyString = NO;
++ (void)setNullToEmpty:(BOOL)empty
+{
+    LKDBNullIsEmptyString = empty;
+}
++ (BOOL)nullIsEmpty
+{
+    return LKDBNullIsEmptyString;
+}
 
 + (NSMutableArray*)dbHelperSingleArray
 {
@@ -595,12 +604,18 @@ - (void)fixSqlColumnsWithClass:(Class)clazz tableName:(NSString*)tableName
                 if (property.defaultValue) {
                     [addColumePars appendFormat:@" %@ %@", LKSQL_Attribute_Default, property.defaultValue];
                 }
-
-                NSString* alertSQL = [NSString stringWithFormat:@"alter table %@ add column %@", tableName, addColumePars];
-                NSString* initColumnValue = [NSString stringWithFormat:@"update %@ set %@=%@", tableName, property.sqlColumnName, [property.sqlColumnType isEqualToString:LKSQL_Type_Text] ? @"null" : @"0"];
-
+                NSString *alertSQL = [NSString stringWithFormat:@"alter table %@ add column %@", tableName, addColumePars];
+                NSString *defaultValue = @"0";
+                if ([property.sqlColumnType isEqualToString:LKSQL_Type_Text]) {
+                    if (LKDBNullIsEmptyString) {
+                        defaultValue = @"";
+                    }
+                    else {
+                        defaultValue = @"null";
+                    }
+                }
+                NSString* initColumnValue = [NSString stringWithFormat:@"update %@ set %@=%@", tableName, property.sqlColumnName, defaultValue];
                 BOOL success = [db executeUpdate:alertSQL];
-
                 if (success) {
                     [db executeUpdate:initColumnValue];
                     [alterAddColumns addObject:property];
@@ -760,7 +775,12 @@ - (id)modelValueWithProperty:(LKDBProperty*)property model:(NSObject*)model
     }
 
     if (value == nil) {
-        value = [NSNull null];
+        if (LKDBNullIsEmptyString) {
+            value = @"";
+        }
+        else {
+            value = [NSNull null];
+        }
     }
 
     return value;

LKDBHelper/Helper/NSObject+LKModel.m

@@ -23,6 +23,10 @@
 static char LKModelBase_Key_TableName;
 static char LKModelBase_Key_Inserting;
 
+@interface LKDBHelper (LKDBHelper_LKModel)
++ (BOOL)nullIsEmpty;
+@end
+
 @implementation NSObject (LKModel)
 
 + (LKDBHelper*)getUsingLKDBHelper
@@ -322,7 +326,9 @@ - (void)modelSetValue:(LKDBProperty *)property value:(NSString *)value
         //不继续遍历
     }
     else if ([columnClass isSubclassOfClass:[NSString class]]) {
-        modelValue = [value copy];
+        if (![LKDBHelper nullIsEmpty] || value.length > 0) {
+            modelValue = [value copy];
+        }
     }
     else if ([columnClass isSubclassOfClass:[NSNumber class]]) {
         modelValue = [[LKDBUtils numberFormatter] numberFromString:value];