前一段时间在弄数据库设计，有时要把一些数据（数据类不大）导到其它类型的数据库里，发现无论是Sql Server、Oracle、MySql，在从库中导出标准的建表和插入数据（即Insert语句）语句时，多少有些不如人意，于是结合自己的要求，自己动手写一个导出的程序。
程序在ListBox（lboxAll）中列出指定的数据库中所有的用户表名，选中要导出的表名将会被添加到另一ListBox（lboxSelected）中，程序将导出lboxSelected中所有表的建表语句以及以Insert语句形式导出的数据：
1）Sql Server：
获得用户表信息
select name tname from sysobjects where xtype='U'
获取表的字段信息
select sysobjects.name table_name,syscolumns.name column_name,systypes.name
data_type,syscolumns.isnullable,syscolumns.length,syscolumns.prec,syscolumns.scale
from sysobjects
join syscolumns
on sysobjects.id=syscolumns.id
join systypes
on syscolumns.xtype=systypes.xtype
where sysobjects.name='tablename'
相关程序（省略部分代码）：
private void ShowAllTable()
{
……
this.cmd.CommandText = "select name tname from sysobjects where xtype='U'";
try
{
this.conn.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "alltable");
this.Invoke((MethodInvoker)delegate
{
this.lboxAll.DataSource = ds.Tables["alltable"].DefaultView;
this.lboxAll.DisplayMember = "tname";
});
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
private void ExpSQL()
{
this.sw = new StreamWriter(this.path,true,Encoding.Default);
try
{
this.conn.Open();
for (int i = 0; i < this.lboxSelected.Items.Count; i++)
{
this.cmd.CommandText ="select sysobjects.name table_name,syscolumns.name
column_name,systypes.name data_type, syscolumns.isnullable,
syscolumns.length,syscolumns.prec,syscolumns.scale";
this.cmd.CommandText +=Environment.NewLine +"from sysobjects";
this.cmd.CommandText +=Environment.NewLine +"join syscolumns";
this.cmd.CommandText +=Environment.NewLine +"on sysobjects.id=syscolumns.id";
this.cmd.CommandText +=Environment.NewLine +"join systypes";
this.cmd.CommandText +=Environment.NewLine +"on syscolumns.xtype=systypes.xtype";
this.cmd.CommandText +=Environment.NewLine +"where sysobjects.name='" +
this.lboxSelected.Items[i].ToString() + "'";
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "colinfo");
DataTable dt = ds.Tables["colinfo"];
this.GenerateCreateStatement(dt);
this.cmd.CommandText = "select * from " + this.lboxSelected.Items[i].ToString();
da = new SqlDataAdapter(cmd);
da.Fill(ds, "datainfo");
DataTable dt2 = ds.Tables["datainfo"];
this.GenerateInsertStatement(dt, dt2);
Thread.Sleep(10);
}
this.sw.Flush();
this.sw.Close();
this.sw.Dispose();
MessageBox.Show("完成", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
private void GenerateCreateStatement(DataTable dt)
{
string sql = "CREATE TABLE " + dt.Rows[0]["TABLE_NAME"].ToString() + "(" +
Environment.NewLine;
for (int i = 0; i < dt.Rows.Count; i++)
{
sql += dt.Rows[i]["COLUMN_NAME"].ToString() + " " + dt.Rows[i]["DATA_TYPE"].ToString();
if (dt.Rows[i]["DATA_TYPE"].ToString() == "varchar" ||
dt.Rows[i]["DATA_TYPE"].ToString() == "char" ||
dt.Rows[i]["DATA_TYPE"].ToString() == "nvarchar" ||
dt.Rows[i]["DATA_TYPE"].ToString() == "nchar")
{
sql += "(" + dt.Rows[i]["LENGTH"].ToString() + ")";
}
if (dt.Rows[i]["DATA_TYPE"].ToString() == "decimal" ||
dt.Rows[i]["DATA_TYPE"].ToString() == "numeric")
{
sql += "(" + dt.Rows[i]["PREC"].ToString();
sql += "," + dt.Rows[i]["SCALE"].ToString();
sql += ")";
}
if (dt.Rows[i]["ISNULLABLE"].ToString() == "0")
{
sql += " NOT NULL";
}
sql += "," + Environment.NewLine;
}
sql = sql.Substring(0, sql.LastIndexOf(',')) + ");" + Environment.NewLine;
this.sw.Write(sql);
this.sw.Write(Environment.NewLine);
}
private void GenerateInsertStatement(DataTable dtColInfo, DataTable dtDataInfo)
{
string sql = "INSERT INTO " + dtColInfo.Rows[0]["TABLE_NAME"].ToString() + "(";
string values = "";
string colName = "";
string dataType = "";
for (int i = 0; i < dtDataInfo.Rows.Count; i++)
{
values = "VALUES(";
for (int j = 0; j < dtColInfo.Rows.Count; j++)
{
colName = dtColInfo.Rows[j]["COLUMN_NAME"].ToString();
dataType = dtColInfo.Rows[j]["DATA_TYPE"].ToString();
if (i == 0)
{
sql += colName + ",";
}
if (dtDataInfo.Rows[i][colName].ToString() == "")
{
values += "NULL,";
}
else
{
if (dataType == "varchar" || dataType == "char" || dataType == "datetime" ||
dataType == "nvarchar" || dataType == "nchar")//小写
{
values += "'" +
dtDataInfo.Rows[i][colName].ToString().Trim().Replace("\'","\'\'") + "',";
}
else//
{
values += dtDataInfo.Rows[i][colName].ToString() + ",";
}
}
}
this.sw.Write(sql.Substring(0, sql.LastIndexOf(',')) + ")" + Environment.NewLine +
values.Substring(0, values.LastIndexOf(',')) + ");"
+ Environment.NewLine);
this.sw.Write(Environment.NewLine);
}
}
2）Oracle：
获得用户表信息
select tname from tab
获取表的字段信息
select * from ALL_TAB_COLUMNS A WHERE A.TABLE_NAME='tablename'
相关程序（省略部分代码）：
private void ShowAllTable()
{
……
this.cmd.CommandText = "select tname from tab";
try
{
this.conn.Open();
OracleDataAdapter da = new OracleDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "alltable");
this.Invoke((MethodInvoker)delegate
{
this.lboxAll.DataSource = ds.Tables["alltable"].DefaultView;
this.lboxAll.DisplayMember = "tname";
});
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
private void ExpSQL()
{
this.sw = new StreamWriter(this.path,true,Encoding.Default);
try
{
this.conn.Open();
for (int i = 0; i < this.lboxSelected.Items.Count; i++)
{
this.cmd.CommandText = "select * from ALL_TAB_COLUMNS A WHERE A.TABLE_NAME='" +
this.lboxSelected.Items[i].ToString()+"'";
OracleDataAdapter da = new OracleDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "colinfo");
DataTable dt = ds.Tables["colinfo"];
this.GenerateCreateStatement(dt);
this.cmd.CommandText = "select * from " + this.lboxSelected.Items[i].ToString();
da = new OracleDataAdapter(cmd);
da.Fill(ds, "datainfo");
DataTable dt2 = ds.Tables["datainfo"];
this.GenerateInsertStatement(dt, dt2);
Thread.Sleep(10);
}
this.sw.Flush();
this.sw.Close();
this.sw.Dispose();
MessageBox.Show("完成", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
private void GenerateCreateStatement(DataTable dt)
{
string sql = "CREATE TABLE " + dt.Rows[0]["TABLE_NAME"].ToString() + "(" +
Environment.NewLine;
for (int i = 0; i < dt.Rows.Count; i++)
{
sql += dt.Rows[i]["COLUMN_NAME"].ToString() + " " + dt.Rows[i]["DATA_TYPE"].ToString();
if (dt.Rows[i]["DATA_TYPE"].ToString() == "VARCHAR2" ||
dt.Rows[i]["DATA_TYPE"].ToString() == "CHAR")
{
sql += "(" + dt.Rows[i]["DATA_LENGTH"].ToString() + ")";
}
if (dt.Rows[i]["DATA_TYPE"].ToString() == "NUMBER" && dt.Rows[i]["DATA_PRECISION"] !=
System.DBNull.Value)
{
sql += "(" + dt.Rows[i]["DATA_PRECISION"].ToString();
if (dt.Rows[i]["DATA_SCALE"].ToString() != "0")
{
sql += "," + dt.Rows[i]["DATA_SCALE"].ToString();
}
sql += ")";
}
if (dt.Rows[i]["NULLABLE"].ToString() == "N")
{
sql += " NOT NULL";
}
sql += "," + Environment.NewLine;
}
sql = sql.Substring(0, sql.LastIndexOf(',')) + ");" + Environment.NewLine;
this.sw.Write(sql);
this.sw.Write(Environment.NewLine);
}
private void GenerateInsertStatement(DataTable dtColInfo, DataTable dtDataInfo)
{
string sql = "INSERT INTO " + dtColInfo.Rows[0]["TABLE_NAME"].ToString() + "(";
string values = "";
string colName = "";
string dataType = "";
for (int i = 0; i < dtDataInfo.Rows.Count; i++)
{
values = "VALUES(";
for (int j = 0; j < dtColInfo.Rows.Count; j++)
{
colName = dtColInfo.Rows[j]["COLUMN_NAME"].ToString();
dataType = dtColInfo.Rows[j]["DATA_TYPE"].ToString();
if (i == 0)
{
sql += colName + ",";
}
if (dtDataInfo.Rows[i][colName].ToString() == "")
{
values += "NULL,";
}
else
{
if (dataType == "VARCHAR2" || dataType == "CHAR")
{
values += "'" +
dtDataInfo.Rows[i][colName].ToString().Trim().Replace("\'", "\'\'") + "',";
}
else if (dataType == "DATE")
{
values += "TO_DATE('" + dtDataInfo.Rows[i][colName].ToString() +
"','yyyy-mm-dd hh24:mi:ss'),";
}
else//
{
values += dtDataInfo.Rows[i][colName].ToString() + ",";
}
}
}
this.sw.Write(sql.Substring(0, sql.LastIndexOf(',')) + ")" + Environment.NewLine +
values.Substring(0, values.LastIndexOf(',')) + ");" + Environment.NewLine);
this.sw.Write(Environment.NewLine);
}
}
3）MySql：
获得用户表信息
show tables;
MySql中可以不必自己去拼建表语句，使用以下Sql获得建表语句
show create table tablename;
获取表的字段信息
show columns from tablename;
相关程序（省略部分代码）：
private void ShowAllTable()
{
……
this.cmd.CommandText = "show tables;";
try
{
this.conn.Open();
MySqlDataAdapter da = new MySqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "alltable");
this.Invoke((MethodInvoker)delegate
{
this.lboxAll.DataSource = ds.Tables["alltable"].DefaultView;
this.lboxAll.DisplayMember = "Tables_in_"+this.tbDatabase.Text.Trim();
});
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
private void ExpSQL()
{
this.sw = new StreamWriter(this.path, true, Encoding.Default);
try
{
this.conn.Open();
for (int i = 0; i < this.lboxSelected.Items.Count; i++)
{
this.cmd.CommandText = "show columns from " +
this.lboxSelected.Items[i].ToString();
MySqlDataAdapter da = new MySqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "colinfo");
DataTable dt = ds.Tables["colinfo"];
this.cmd.CommandText = "select * from " + this.lboxSelected.Items[i].ToString();
da = new MySqlDataAdapter(cmd);
da.Fill(ds, "datainfo");
DataTable dt2 = ds.Tables["datainfo"];
this.GenerateCreateStatement(this.lboxSelected.Items[i].ToString());//
this.GenerateInsertStatement(dt, dt2, this.lboxSelected.Items[i].ToString());
Thread.Sleep(10);
}
this.sw.Flush();
this.sw.Close();
this.sw.Dispose();
MessageBox.Show("完成", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
}
private void GenerateCreateStatement(string tname)
{
string sql = "";
try
{
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
this.cmd.CommandText ="show create table " + tname;
MySqlDataReader dr = this.cmd.ExecuteReader();
if (dr.Read())
{
sql = dr["Create Table"].ToString();
}
}
catch (Exception x)
{
MessageBox.Show(x.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
sql = sql.Replace("`", "") + ";" + Environment.NewLine;
this.sw.Write(sql);
this.sw.Write(Environment.NewLine);
}
private void GenerateInsertStatement(DataTable dtColInfo, DataTable dtDataInfo,string tname)
{
string sql = "INSERT INTO " + tname + "(";
string values = "";
string colName = "";
string dataType = "";
for (int i = 0; i < dtDataInfo.Rows.Count; i++)
{
values = "VALUES(";
for (int j = 0; j < dtColInfo.Rows.Count; j++)
{
colName = dtColInfo.Rows[j]["Field"].ToString();
dataType = dtColInfo.Rows[j]["Type"].ToString();
if (i == 0)
{
sql += colName + ",";
}
if (dtDataInfo.Rows[i][colName].ToString() == "")
{
values += "NULL,";
}
else
{
if (dataType.StartsWith("varchar") || dataType.StartsWith("char") ||
dataType == "datetime" || dataType == "date")
{
values += "'" +
dtDataInfo.Rows[i][colName].ToString().Trim().Replace("\'", "\'\'") + "',";
}
else//
{
values += dtDataInfo.Rows[i][colName].ToString() + ",";
}
}
}
this.sw.Write(sql.Substring(0, sql.LastIndexOf(',')) + ")" + Environment.NewLine +
values.Substring(0, values.LastIndexOf(',')) + ");" + Environment.NewLine);
this.sw.Write(Environment.NewLine);
}
}
程序里有好些方面是没有处理的，包括：表名、字段名为数据库保留字；表名、字段名含有特殊字符（如空格）；一些数据类型没有处理，如Sql Server中的Float型等；主、外键的声明；对大对象类型没有处理等等等等，只是原理上大抵是如此。
对于MySql导出Insert语句，如果不是要移到其它类型的数据库上，用MySqlDump命令是OK，不用上面这么麻烦。
顺便抱怨一下各数据库的图型界面，Sql Server是OK的，企业管理器和查询分析器用起来很好。
对于MySql的图形界面，用的多的好像是“mysql front”，一个字，烂！只要数据库中表较多（几十张）或者表中数据较多（几千行）时，就死机（机器配置很好的前提下）。后来上mysql官网上下了“mysql query browser”，一样有问题，首先，每次只能执行一条语句，其次，只要语句中有汉字，马上死，两个字，烂啊！
对于Oracle，不知道大家都在用什么界面，这里用的是“oraedit”，倒是不死，只是在编写存储过程或执行存储过程时，不时有莫名其妙的问题。
