为什么ExecuteNonQuery捕获异常{“列的验证错误”ORGTABLE \“。\”FIKEYID \“，值\”* null * \“”}

Question

为什么ExecuteNonQuery捕获异常{“列验证错误”ORGTABLE \“。\”FIKEYID \“，值\” * null * \“”}

string stValuesPlaceHolder = "@p0";
for (int iii = 1; iii < liststFieldValuesNoKeyId.Count; iii++)
    stValuesPlaceHolder += ", @p" + (iii).ToString();

FbTransaction fbTransaction = fbConn.BeginTransaction();
FbCommand fbCmd = new FbCommand("INSERT INTO " + stTableName + "(" + stFieldNamesNoKeyId + ") VALUES ( " + stValuesPlaceHolder + " )", fbConn, fbTransaction);

for (int iii = 0; iii < liststFieldValuesNoKeyId.Count; iii++) {
    string stPlaceHolder = "@p" + (iii).ToString();
    string stValue = liststFieldValuesNoKeyId[iii];
    fbCmd.Parameters.AddWithValue(stPlaceHolder, stValue);
}

fbCmd.ExecuteNonQuery();
fbTransaction.Commit();

stTableName是OrgTable。

字段名称为：

fstPriority, fstInfo, fstDateCreated, fstDateModified, fiKeyID.

字段定义是：

fstPriority VARCHAR(30), fstInfo VARCHAR(100), fstDateCreated VARCHAR(30), fstDateModified VARCHAR(30), fiKeyID INTEGER PRIMARY KEY

在代码的这一部分：

stFieldNamesNoKeyId = "fstPriority, fstInfo, fstDateCreated, fstDateModified".

stValuesPlaceHolder = "@p0, @p1, @p2, @p3"

四     fbCmd.Parameters.AddWithValue：

stPlaceHolder = "@p0" ... stValue = "1st value";

stPlaceHolder = "@p1" ... stValue = "2nd value";

stPlaceHolder = "@p2" ... stValue = "3rd value";

stPlaceHolder = "@p3" ... stValue = "4th value";

我没有添加fiKeyID的值，因为它与PRIMARY KEY一样。

Answer 1

  

我没有添加fiKeyID的值，因为它与PRIMARY KEY一样。

因此，您尝试插入NULL主键。这是不允许的。

http://www.firebirdsql.org/manual/nullguide-keys.html

  

主键中绝不允许使用NULL。如果列已定义为NOT NULL，则列只能是（PK的一部分），无论是在列定义中还是在域定义中。

然后，您可能想要求服务器自动生成ID。这样做的方法很少。

例如，Firebird 3附带auto-inc列类型。 这是一种语法糖，而不是数据库开发人员之前明确使用过的工具。

Firebird 2和之前的版本使用GENERATORS（又名SQL SEQUENCE）来实现它。

如果ID字段为NULL，则必须在表上进行BEFORE-INSERT（或BEFORE-INSERT-OR-UPDATE）触发器，该触发器将填充生成器的ID字段。 http://www.firebirdfaq.org/faq29/

CREATE GENERATOR gen_t1_id;
SET GENERATOR gen_t1_id TO 0;
set term !! ;
 CREATE TRIGGER T1_BI FOR T1
 ACTIVE BEFORE INSERT POSITION 0
 AS
 BEGIN
 if (NEW.ID is NULL) then NEW.ID = GEN_ID(GEN_T1_ID, 1);
 END!!
set term ; !!

归结为您的SQL访问库。 因为通常在您插入行之后 - 您必须知道它的ID。

如果您不关心新生儿行的ID，您可以跳过其余部分。

但是如果你想要插入行并知道它的ID，那么它归结为另一种选择。

低技术的SQL专用库会迫使你采取双线路：

• SELECT GEN_ID(GEN_T1_ID, 1) FROM RDB$DATABASE或SELECT NEXT VALUE FOR GEN_T1_ID FROM RDB$DATABASE会为您保留一个免费令牌，然后您将明确地将您的ID PK列分配给该值，并将其与数据列一起插入，绕过触发器。< / p>

• 或者使用高级SQL库，您可以要求Firebird自动计算值并将其报告给您：INSERT INTO tablename(data1,data2,dataq3) VALUES (1,2,3) RETURNING id。请参阅https://en.wikipedia.org/wiki/Insert_(SQL)#Retrieving_the_key

是否需要学习插入的ID，以及SQL库是否支持INSERT-RETURNING命令 - 由您自行决定。

但是当我进行谷歌搜索（它是www.google.com）时，它会为许多不同的C＃SQL库提供许多关于C# Firebird Insert Returniung的链接，而且只有你可以告诉你使用哪一个。对于来自不同库的少数示例：

• http://www.ibprovider.com/eng/documentation/firebird_21_adonet.html
• http://www.sql.ru/forum/actualutils.aspx?action=gotomsg&tid=720869&msg=8075816
• Retrieve last id from Firebird db table
• Firebird insert...returning asp.net
• https://social.msdn.microsoft.com/Forums/en-US/e7099cfb-7809-460a-aae9-79a2bd703454/how-i-can-return-the-id-after-insert-a-record-into-a-database-firebird-25-with-linq?forum=adodotnetentityframework

等等

Answer 2

说明：

public const string stMAIN_TABLE_NAME = " OrgTable ";
public const string stDELETED_TABLE_NAME = "  BackupTable ";

public const string stFIELD_DEFINITIONS = " fstPriority VARCHAR(30)" + 
                                          ", fstInfo VARCHAR(100)" +
                                          ", fstDateCreated VARCHAR(30)" +
                                          ", fstDateModified VARCHAR(30)" +
                                          ", fiKeyID INTEGER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY ";

public const string stFIELD_NAMES_NO_KEY_ID = " fstPriority" + 
                                              ", fstInfo" + 
                                              ", fstDateCreated" + 
                                              ", fstDateModified ";

public const string stFIELD_NAMES_KEY_ID = " fiKeyID ";

public const string stFIELD_NAMES = stFIELD_NAMES_NO_KEY_ID + ", " + stFIELD_NAMES_KEY_ID;

代码：

//------------------------------
static private bool boCreateDatabaseTables(string stPathFilename, 
                                           string stUserID, 
                                           string stPassword, 
                                           List<string> liststTableNames, 
                                           List<string> liststFieldDefinitions) 
{
  bool boErrorFlag = false;
  int iTablesCount = liststTableNames.Count();
  string stOpenConn = new FbConnectionStringBuilder {
    Database = stPathFilename,
    UserID = stUserID,
    Password = stPassword,
    ServerType = FbServerType.Embedded,
    ClientLibrary = stCLIENT_LIBRARY
    }.ToString();
  using (FbConnection fbConn = new FbConnection(stOpenConn)) {
    try {
      fbConn.Open();

      FbTransaction fbTransaction = fbConn.BeginTransaction();
      for (int ii = 0; ii < iTablesCount; ii++) {
        string stSql = "CREATE TABLE " + liststTableNames[ii] + "( " + liststFieldDefinitions[ii] + ")";
        FbCommand fbCmd = new FbCommand(stSql, fbConn, fbTransaction);
        fbCmd.ExecuteNonQuery();
      }
      fbTransaction.Commit();
    }
    catch (Exception ex) {
      boErrorFlag = true;
      MessageBox.Show("catch ... GlobalsFirebird ... boCreateDatabaseTables ... " + ex.Message);
    }
}
return boErrorFlag;
}//boCreateDatabaseTables
//------------------------------
//------------------------------
static public bool boAddRow(string stPathFilename,
                            string stUserID,
                            string stPassword,
                            string stTableName,
                            string stFieldNamesNoKeyId,
                            string stFieldNamesKeyId,
                            List<string> liststFieldValuesNoKeyId) 
{
  bool boErrorFlag = false;
  string stOpenConn = new FbConnectionStringBuilder {
    Database = stPathFilename,
    UserID = stUserID,
    Password = stPassword,
    ServerType = FbServerType.Embedded,
    ClientLibrary = stCLIENT_LIBRARY
  }.ToString();

  using(FbConnection fbConn = new FbConnection(stOpenConn)) {
    fbConn.Open();
    try {
      string stValuesPlaceHolder = "@p0";
      for (int iii = 1; iii < liststFieldValuesNoKeyId.Count; iii++)
        stValuesPlaceHolder += ", @p" + (iii).ToString();
      FbTransaction fbTransaction = fbConn.BeginTransaction();
      string stCmd = "INSERT INTO " + stTableName + "(" + stFieldNamesNoKeyId + ") VALUES ( " + stValuesPlaceHolder + " ) RETURNING  " + stFieldNamesKeyId;
      FbCommand fbCmd = new FbCommand(stCmd, fbConn, fbTransaction);

      for (int iii = 0; iii < liststFieldValuesNoKeyId.Count; iii++) {
        string stPlaceHolder = "@p" + (iii).ToString();
        string stValue = liststFieldValuesNoKeyId[iii];
        fbCmd.Parameters.AddWithValue(stPlaceHolder, stValue);
      }
      fbCmd.Parameters.Add(new FbParameter() { Direction = System.Data.ParameterDirection.Output });
      fbCmd.ExecuteNonQuery();
      fbTransaction.Commit();
    }
    catch (Exception ex) {
      boErrorFlag = true;
      MessageBox.Show("catch ... GlobalsFirebird ... boAddRow ... " + ex.Message);
    }
  }
  return boErrorFlag;
}//boAddRow
//------------------------------