Gets or sets the DbExpression that defines the left argument.
Assembly: System.Data.Entity (in System.Data.Entity.dll)
Derived expression types might perform stricter type checks when the property is set. For example, DbUnionAllExpression requires that its left expression has a collection result type, while DbAndExpression requires a Boolean result type. Typically, derived expression types will not allow to be set to an expression with a result type that is not equal or promotable to the result type of the current value.