/// <summary>
/// 更新大文本字符串保存到数据库
/// 王方圆添加 2017-5-16
/// </summary>
/// <param name="tableName">表明</param>
/// <param name="id">唯一标识ID</param>
/// <param name="longTextFieldName">字段名称</param>
/// <param name="longTextContent">更新文本内容</param>
public static void UpdateLongText(string tableName, long id, string longTextFieldName, string longTextContent)
{
string connectStr = System.Configuration.ConfigurationManager.ConnectionStrings["DefaultDB"].ConnectionString;
using (Oracle.DataAccess.Client.OracleConnection conn = new Oracle.DataAccess.Client.OracleConnection(connectStr))
{
conn.Open();
//OracleTransaction trans = conn.BeginTransaction();
Oracle.DataAccess.Client.OracleCommand cmd = conn.CreateCommand();
//cmd.Transaction = trans;
cmd.CommandText = "declare xx clob; begin dbms_lob.createtemporary(xx, false, 0); :templob := xx; end;";
cmd.Parameters.Add(new Oracle.DataAccess.Client.OracleParameter(":templob", Oracle.DataAccess.Client.OracleDbType.Clob)).Direction = ParameterDirection.Output;
cmd.ExecuteNonQuery();
OracleClob tmplob = (OracleClob)cmd.Parameters[0].Value;
byte[] buffer = System.Text.Encoding.Unicode.GetBytes(longTextContent);
tmplob.Write(buffer, 0, buffer.Length);
tmplob.Position = 0;
cmd.Parameters.Clear();
string cmdText = "update {0} set {1} = :lob where EMAIL_ID= :id";
cmdText = string.Format(cmdText, tableName, longTextFieldName);
cmd.CommandText = cmdText;
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add(new Oracle.DataAccess.Client.OracleParameter(":lob", Oracle.DataAccess.Client.OracleDbType.Clob)).Value = tmplob;
cmd.Parameters.Add(new Oracle.DataAccess.Client.OracleParameter(":id", id));
cmd.ExecuteNonQuery();
}
}