ColumnExpression.MakeNullable 方法 參考 意見反應 定義 命名空間: Microsoft.EntityFrameworkCore.Query.SqlExpressions 組件: Microsoft.EntityFrameworkCore.Relational.dll 套件: Microsoft.EntityFrameworkCore.Relational v
Column col21; col21 = new Column(tb, "Number", DataType.Int); col21.Nullable = false; tb.Columns.Add(col21); // Create the table of the instance of SQL Server. tb.Create(); // Create a unique, clustered, primary key index on the integer column. This is required ...
is_nullable位元1= 資料行可為 Null 0= 資料行不可為 Null is_ansi_padded位元1= 如果字元、二進位或變體,數據行會使用ANSI_PADDING ON行為 0= 資料行不是字元、二進位或變體 is_rowguidcol位元1= Column 是宣告的ROWGUIDCOL is_identity位元1= 資料行具有識別值 ...
ColumnNullableUnknown FunctionColumnIn FunctionColumnInOut FunctionColumnOut FunctionColumnResult FunctionColumnUnknown FunctionNoNulls FunctionNoTable FunctionNullable FunctionNullableUnknown FunctionResultUnknown FunctionReturn FunctionReturnsTable ImportedKeyCascade ImportedKeyInitiallyDeferred ImportedKeyInitiallyImmediate Imp...
DDLAllowChangeColumnPosition DDL 允许使用after/first AllowCreateView DDL 允许创建视图 AllowCreatePartition DDL 允许创建分区 AllowSpecialType DDL 允许添加bit,enum,set类型字段 SupportCollation DDL create/alter 表或字段时允许的Collate范围。多个请使用逗号进行分割 SupportCharset DDL create/alter 表或字...
id=Column(Integer,primary_key=True,autoincrement=True) bname=Column(String(32),nullable=False,index=True) #多对一:多个服务可以属于一个业务线,多个业务线不能包含同一个服务 class Service(Base): __tablename__='service' id=Column(Integer,primary_key=True,autoincrement=True) ...
a column withINTOthe column is defined as nullable if the expression that defined it is nullable...
ColumnNoNulls ColumnNullable ColumnNullableUnknown Properties Methods IRowId ISavepoint ISQLData ISQLInput ISQLOutput ISQLXML IStatement IStruct IWrapper ParameterMetaData ResultSet ResultSetMetaData RowIdLifetime SQLClientInfoException SQLDataException ...
("id", Integer, primary_key=True), Column("a", Integer(), nullable=False), Column("b", Integer(), nullable=False), Column("c", Integer(), nullable=False), ) engine = create_engine("mysql+mysqldb://scott:tiger@localhost/test", echo=True) sess = Session(engine) now = time.time...
status= Column(String(32), nullable=False) stu_id= Column(INTEGER, ForeignKey('student.id')) student= relationship("Student", backref="stu_rec")#允许在Student表通过backref字段反向查询它在StudentRecord表里的关联数#同理,在StudentRecord表中可以通过student实例查询它在Student表里的关联数据def__repr_...