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。