SqlParameterCollection.Add 方法
定义
重要
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向 SqlParameter 中添加一个 SqlParameterCollection。
重载
Add(SqlParameter) |
将指定的 SqlParameter 对象添加到 SqlParameterCollection 中。 |
Add(Object) |
将指定的 SqlParameter 对象添加到 SqlParameterCollection 中。 |
Add(String, SqlDbType) |
在给定参数名称和数据类型时向 SqlParameter 中添加一个 SqlParameterCollection。 |
Add(String, Object) |
已过时.
将指定的 SqlParameter 对象添加到 SqlParameterCollection 中。 |
Add(String, SqlDbType, Int32) |
将 SqlParameter 添加到 SqlParameterCollection 中(给定了指定的参数名、SqlDbType 和大小)。 |
Add(String, SqlDbType, Int32, String) |
使用给定的参数名称、数据类型和列长度向 SqlParameter 中添加一个 SqlParameterCollection。 |
Add(SqlParameter)
将指定的 SqlParameter 对象添加到 SqlParameterCollection 中。
public:
System::Data::SqlClient::SqlParameter ^ Add(System::Data::SqlClient::SqlParameter ^ value);
public System.Data.SqlClient.SqlParameter Add (System.Data.SqlClient.SqlParameter value);
override this.Add : System.Data.SqlClient.SqlParameter -> System.Data.SqlClient.SqlParameter
member this.Add : System.Data.SqlClient.SqlParameter -> System.Data.SqlClient.SqlParameter
Public Function Add (value As SqlParameter) As SqlParameter
参数
- value
- SqlParameter
要添加到集合中的 SqlParameter。
返回
一个新 SqlParameter 对象。
例外
在 value
参数中指定的 SqlParameter 已经添加到这个或其他 SqlParameterCollection 中。
传递的参数不是 SqlParameter。
value
参数为 null。
示例
public void AddSqlParameter(SqlCommand command)
{
command.Parameters.Add(new SqlParameter("Description", "Beverages"));
}
Public Sub AddSqlParameter(command As SqlCommand)
command.Parameters.Add(New SqlParameter("Description", "Beverages"))
End Sub
另请参阅
适用于
Add(Object)
将指定的 SqlParameter 对象添加到 SqlParameterCollection 中。
public:
override int Add(System::Object ^ value);
public:
virtual int Add(System::Object ^ value);
public override int Add (object value);
public int Add (object value);
override this.Add : obj -> int
abstract member Add : obj -> int
override this.Add : obj -> int
Public Overrides Function Add (value As Object) As Integer
Public Function Add (value As Object) As Integer
参数
返回
新的 SqlParameter 对象的索引。
实现
示例
下面的示例演示 IList 接口的实现以创建具有固定大小的简单列表。 此代码是 接口的更大示例的 IList 一部分。
class SimpleList : IList
{
private object[] _contents = new object[8];
private int _count;
public SimpleList()
{
_count = 0;
}
// IList Members
public int Add(object value)
{
if (_count < _contents.Length)
{
_contents[_count] = value;
_count++;
return (_count - 1);
}
return -1;
}
public void Clear()
{
_count = 0;
}
public bool Contains(object value)
{
for (int i = 0; i < Count; i++)
{
if (_contents[i] == value)
{
return true;
}
}
return false;
}
public int IndexOf(object value)
{
for (int i = 0; i < Count; i++)
{
if (_contents[i] == value)
{
return i;
}
}
return -1;
}
public void Insert(int index, object value)
{
if ((_count + 1 <= _contents.Length) && (index < Count) && (index >= 0))
{
_count++;
for (int i = Count - 1; i > index; i--)
{
_contents[i] = _contents[i - 1];
}
_contents[index] = value;
}
}
public bool IsFixedSize
{
get
{
return true;
}
}
public bool IsReadOnly
{
get
{
return false;
}
}
public void Remove(object value)
{
RemoveAt(IndexOf(value));
}
public void RemoveAt(int index)
{
if ((index >= 0) && (index < Count))
{
for (int i = index; i < Count - 1; i++)
{
_contents[i] = _contents[i + 1];
}
_count--;
}
}
public object this[int index]
{
get
{
return _contents[index];
}
set
{
_contents[index] = value;
}
}
// ICollection members.
public void CopyTo(Array array, int index)
{
for (int i = 0; i < Count; i++)
{
array.SetValue(_contents[i], index++);
}
}
public int Count
{
get
{
return _count;
}
}
public bool IsSynchronized
{
get
{
return false;
}
}
// Return the current instance since the underlying store is not
// publicly available.
public object SyncRoot
{
get
{
return this;
}
}
// IEnumerable Members
public IEnumerator GetEnumerator()
{
// Refer to the IEnumerator documentation for an example of
// implementing an enumerator.
throw new NotImplementedException("The method or operation is not implemented.");
}
public void PrintContents()
{
Console.WriteLine($"List has a capacity of {_contents.Length} and currently has {_count} elements.");
Console.Write("List contents:");
for (int i = 0; i < Count; i++)
{
Console.Write($" {_contents[i]}");
}
Console.WriteLine();
}
}
Public Class SimpleList
Implements IList
Private _contents(7) As Object
Private _count As Integer
Public Sub New()
_count = 0
End Sub
' IList members.
Public Function Add(ByVal value As Object) As Integer Implements IList.Add
If _count < _contents.Length Then
_contents(_count) = value
_count += 1
Return _count - 1
End If
Return -1
End Function
Public Sub Clear() Implements IList.Clear
_count = 0
End Sub
Public Function Contains(ByVal value As Object) As Boolean Implements IList.Contains
For i As Integer = 0 To Count - 1
If _contents(i) = value Then Return True
Next
Return False
End Function
Public Function IndexOf(ByVal value As Object) As Integer Implements IList.IndexOf
For i As Integer = 0 To Count - 1
If _contents(i) = value Then Return i
Next
Return -1
End Function
Public Sub Insert(ByVal index As Integer, ByVal value As Object) Implements IList.Insert
If _count + 1 <= _contents.Length AndAlso index < Count AndAlso index >= 0 Then
_count += 1
For i As Integer = Count - 1 To index Step -1
_contents(i) = _contents(i - 1)
Next
_contents(index) = value
End If
End Sub
Public ReadOnly Property IsFixedSize() As Boolean Implements IList.IsFixedSize
Get
Return True
End Get
End Property
Public ReadOnly Property IsReadOnly() As Boolean Implements IList.IsReadOnly
Get
Return False
End Get
End Property
Public Sub Remove(ByVal value As Object) Implements IList.Remove
RemoveAt(IndexOf(value))
End Sub
Public Sub RemoveAt(ByVal index As Integer) Implements IList.RemoveAt
if index >= 0 AndAlso index < Count Then
for i As Integer = index To Count - 2
_contents(i) = _contents(i + 1)
Next
_count -= 1
End If
End Sub
Public Property Item(ByVal index As Integer) As Object Implements IList.Item
Get
Return _contents(index)
End Get
Set(ByVal value As Object)
_contents(index) = value
End Set
End Property
' ICollection members.
Public Sub CopyTo(ByVal array As Array, ByVal index As Integer) Implements ICollection.CopyTo
For i As Integer = 0 To Count - 1
array.SetValue(_contents(i), index)
index += 1
Next
End Sub
Public ReadOnly Property Count() As Integer Implements ICollection.Count
Get
Return _count
End Get
End Property
Public ReadOnly Property IsSynchronized() As Boolean Implements ICollection.IsSynchronized
Get
Return False
End Get
End Property
' Return the current instance since the underlying store is not
' publicly available.
Public ReadOnly Property SyncRoot() As Object Implements ICollection.SyncRoot
Get
Return Me
End Get
End Property
' IEnumerable members.
Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator
' Refer to the IEnumerator documentation for an example of
' implementing an enumerator.
Throw New NotImplementedException("The method or operation is not implemented.")
End Function
Public Sub PrintContents()
Console.WriteLine($"List has a capacity of {_contents.Length} and currently has {_count} elements.")
Console.Write("List contents:")
For i As Integer = 0 To Count - 1
Console.Write($" {_contents(i)}")
Next
Console.WriteLine()
End Sub
End Class
注解
此成员是显式接口成员的实现。 它只能在 SqlParameterCollection 实例被强制转换为 IList 接口时使用。
另请参阅
适用于
Add(String, SqlDbType)
在给定参数名称和数据类型时向 SqlParameter 中添加一个 SqlParameterCollection。
public:
System::Data::SqlClient::SqlParameter ^ Add(System::String ^ parameterName, System::Data::SqlDbType sqlDbType);
public System.Data.SqlClient.SqlParameter Add (string parameterName, System.Data.SqlDbType sqlDbType);
override this.Add : string * System.Data.SqlDbType -> System.Data.SqlClient.SqlParameter
member this.Add : string * System.Data.SqlDbType -> System.Data.SqlClient.SqlParameter
Public Function Add (parameterName As String, sqlDbType As SqlDbType) As SqlParameter
参数
- parameterName
- String
参数的名称。
返回
一个新 SqlParameter 对象。
示例
public void AddSqlParameter(SqlCommand command)
{
SqlParameter param = command.Parameters.Add(
"@Description", SqlDbType.NVarChar);
param.Size = 16;
param.Value = "Beverages";
}
Public Sub AddSqlParameter(command As SqlCommand)
Dim param As SqlParameter = command.Parameters.Add( _
"@Description", SqlDbType.NVarChar)
param.Size = 16
param.Value = "Beverages"
End Sub
另请参阅
适用于
Add(String, Object)
注意
Add(String parameterName, Object value) has been deprecated. Use AddWithValue(String parameterName, Object value). http://go.microsoft.com/fwlink/?linkid=14202
将指定的 SqlParameter 对象添加到 SqlParameterCollection 中。
public:
System::Data::SqlClient::SqlParameter ^ Add(System::String ^ parameterName, System::Object ^ value);
public System.Data.SqlClient.SqlParameter Add (string parameterName, object value);
[System.Obsolete("Add(String parameterName, Object value) has been deprecated. Use AddWithValue(String parameterName, Object value). http://go.microsoft.com/fwlink/?linkid=14202", false)]
public System.Data.SqlClient.SqlParameter Add (string parameterName, object value);
member this.Add : string * obj -> System.Data.SqlClient.SqlParameter
[<System.Obsolete("Add(String parameterName, Object value) has been deprecated. Use AddWithValue(String parameterName, Object value). http://go.microsoft.com/fwlink/?linkid=14202", false)>]
override this.Add : string * obj -> System.Data.SqlClient.SqlParameter
Public Function Add (parameterName As String, value As Object) As SqlParameter
参数
- parameterName
- String
要添加到集合的 SqlParameter 的名称。
返回
一个新 SqlParameter 对象。
使用 SqlParameterCollection.Add
方法的重载来指定整数参数值时,请务必谨慎。 因为此重载接受 Object 类型的 value
,所以当此值为零时,必须将整数值转换为 Object 类型,如下面的 C# 示例所示。
parameters.Add("@pname", Convert.ToInt32(0));
如果不执行此转换,编译器将假定您正尝试调用 SqlParameterCollection.Add
(string
,SqlDbType
) 重载。
- 属性
例外
在 value
参数中指定的 SqlParameter 已经添加到这个或其他 SqlParameterCollection 中。
value
参数为 null。
示例
public void AddSqlParameter(SqlCommand command)
{
SqlParameter param = new SqlParameter(
"@Description", SqlDbType.NVarChar, 16);
param.Value = "Beverages";
command.Parameters.Add(param);
}
Public Sub AddSqlParameter(command As SqlCommand)
Dim param As New SqlParameter( _
"@Description", SqlDbType.NVarChar, 16)
param.Value = "Beverages"
command.Parameters.Add(param)
End Sub
另请参阅
适用于
Add(String, SqlDbType, Int32)
将 SqlParameter 添加到 SqlParameterCollection 中(给定了指定的参数名、SqlDbType 和大小)。
public:
System::Data::SqlClient::SqlParameter ^ Add(System::String ^ parameterName, System::Data::SqlDbType sqlDbType, int size);
public System.Data.SqlClient.SqlParameter Add (string parameterName, System.Data.SqlDbType sqlDbType, int size);
override this.Add : string * System.Data.SqlDbType * int -> System.Data.SqlClient.SqlParameter
member this.Add : string * System.Data.SqlDbType * int -> System.Data.SqlClient.SqlParameter
Public Function Add (parameterName As String, sqlDbType As SqlDbType, size As Integer) As SqlParameter
参数
- parameterName
- String
参数的名称。
- sqlDbType
- SqlDbType
要添加到集合中的 SqlParameter 的 SqlDbType。
返回
一个新 SqlParameter 对象。
示例
public void AddSqlParameter(SqlCommand command)
{
SqlParameter param = new SqlParameter(
"@Description", SqlDbType.NVarChar, 16);
param.Value = "Beverages";
command.Parameters.Add(param);
}
Public Sub AddSqlParameter(command As SqlCommand)
Dim param As New SqlParameter( _
"@Description", SqlDbType.NVarChar, 16)
param.Value = "Beverages"
command.Parameters.Add(param)
End Sub
注解
添加长度可变数据类型的参数(如 varchar
或 binary
)时,此重载非常有用。
另请参阅
适用于
Add(String, SqlDbType, Int32, String)
使用给定的参数名称、数据类型和列长度向 SqlParameter 中添加一个 SqlParameterCollection。
public:
System::Data::SqlClient::SqlParameter ^ Add(System::String ^ parameterName, System::Data::SqlDbType sqlDbType, int size, System::String ^ sourceColumn);
public System.Data.SqlClient.SqlParameter Add (string parameterName, System.Data.SqlDbType sqlDbType, int size, string sourceColumn);
member this.Add : string * System.Data.SqlDbType * int * string -> System.Data.SqlClient.SqlParameter
override this.Add : string * System.Data.SqlDbType * int * string -> System.Data.SqlClient.SqlParameter
Public Function Add (parameterName As String, sqlDbType As SqlDbType, size As Integer, sourceColumn As String) As SqlParameter
参数
- parameterName
- String
参数的名称。
- size
- Int32
列的长度。
- sourceColumn
- String
源列名 (SourceColumn)(如果在调用 Update 中使用了此 SqlParameter)。
返回
一个新 SqlParameter 对象。
示例
public void AddSqlParameter(SqlCommand cmd)
{
SqlParameter p1 = cmd.Parameters.Add("@Description", SqlDbType.NVarChar, 16, "Description");
}
Public Sub AddSqlParameter(cmd As SqlCommand)
Dim p1 As SqlParameter = cmd.Parameters.Add("@Description", SqlDbType.NVarChar, 16, "Description")
End Sub