合并两个SQLite数据库文件（C＃.NET）

我正在使用C＃/ .NET和SQLite的C＃包装器。 我正在尝试将两个SQLite数据库合并在一起，同时排除重复项。

我找到了这个，这是从几个不同的论坛问题中引用的。 http://old.nabble.com/Attempting-to-merge-large-databases-td18131366.html

我尝试了下面的查询，我从我提供的链接构建，但它们导致exception，数据库根本没有合并，并且原始数据库不会发生任何变化。

attach 'c:\test\b.db3' as toMerge; insert into AuditRecords select * from toMerge.AuditRecords; 

这是我的查询代码。

 public void importData(String fileLoc) { SQLiteTransaction trans; string SQL = "ATTACH '" + fileLoc + "' AS TOMERGE"; SQLiteCommand cmd = new SQLiteCommand(SQL); cmd.Connection = connection; connection.Open(); trans = connection.BeginTransaction(); int retval = 0; try { retval = cmd.ExecuteNonQuery(); } catch (Exception) { trans.Rollback(); MessageBox.Show("An error occurred, your import was not completed."); } finally { trans.Commit(); cmd.Dispose(); connection.Close(); } SQL = "INSERT INTO SUBCONTRACTOR SELECT * FROM TOMERGE.SUBCONTRACTOR"; cmd = new SQLiteCommand(SQL); cmd.Connection = connection; connection.Open(); trans = connection.BeginTransaction(); retval = 0; try { retval = cmd.ExecuteNonQuery(); } catch (Exception) { trans.Rollback(); MessageBox.Show("An error occurred, your import was not completed."); } finally { trans.Commit(); cmd.Dispose(); connection.Close(); } } 

我的问题是，我做错了什么？ 是否有人熟悉insert命令？ 我不确定它是否会在我需要时排除重复项。

Answer 1

在SQLite中附加数据库时，需要在单个Connection / Transaction中执行每个语句（无论是插入，更新，删除）。 不要在两者之间关闭连接。 它应该在单个交易中完成。

试试这个

 public void importData(String fileLoc) { string SQL = "ATTACH '" + fileLoc + "' AS TOMERGE"; SQLiteCommand cmd = new SQLiteCommand(SQL); cmd.Connection = connection; connection.Open(); int retval = 0; try { retval = cmd.ExecuteNonQuery(); } catch (Exception) { MessageBox.Show("An error occurred, your import was not completed."); } finally { cmd.Dispose(); } SQL = "INSERT INTO SUBCONTRACTOR SELECT * FROM TOMERGE.SUBCONTRACTOR"; cmd = new SQLiteCommand(SQL); cmd.Connection = connection; retval = 0; try { retval = cmd.ExecuteNonQuery(); } catch (Exception) { MessageBox.Show("An error occurred, your import was not completed."); } finally { cmd.Dispose(); connection.Close(); } }