CodeSmith7代碼生成器針對PostgreSQL數據庫無法使用的Bug修復全過程

前言

     最近公司需要將原來使用的MSSQL數據庫整體遷移至pgsql，需要使用CodeSmith生成IBatisNet的配置文件。按照提示安裝了Npgsql.dll后依然無法使用。引發了本次通過反編譯修復相關的Bug。主要修復了一下錯誤：

     1、未能加載文件或程序集“Npgsql, Version=2.2.0.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7”

     2、無法查看列信息

     3、缺少表、列自描述

一、使用ILSpy反編譯SchemaExplorer.PostgreSQLSchemaProvider.dll

     打開ILSpy，將SchemaExplorer.PostgreSQLSchemaProvider.dll附加至ILSpy，如下圖所示：

     

二、針對反編譯的代碼進行錯誤修復（詳細修復過程略過）。

三、主要修復函數。

      GetTables、GetTableColumns、GetTablePrimaryKey、GetTableKeys。因為我所使用的功能僅限於這幾個函數所以只針對該相關的方法錯誤進行了修復。

      1、修復表架構缺少描述的Bug

       GetTables反編譯的關鍵源碼

public TableSchema[] GetTables(string connectionString, DatabaseSchema database)
{
    List<TableSchema> list = new List<TableSchema>();
    using (NpgsqlConnection npgsqlConnection = new NpgsqlConnection(connectionString))
    {
        npgsqlConnection.Open();
        using (NpgsqlCommand npgsqlCommand = new NpgsqlCommand("select tablename, tableowner from pg_catalog.pg_tables where schemaname = 'public' order by tablename", npgsqlConnection))
        {
            using (NpgsqlDataReader npgsqlDataReader = npgsqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
            {
                while (npgsqlDataReader.Read())
                {
                    if (npgsqlDataReader.GetString(0).ToUpper() != "CODESMITH_EXTENDED_PROPERTIES")
                    {
                        list.Add(new TableSchema(database, npgsqlDataReader.GetString(0), npgsqlDataReader.GetString(1), DateTime.MinValue));
                    }
                }
                if (!npgsqlDataReader.IsClosed)
                {
                    npgsqlDataReader.Close();
                }
            }
        }
        if (npgsqlConnection.State != ConnectionState.Closed)
        {
            npgsqlConnection.Close();
        }
    }
    return list.ToArray();
}

           修復的源碼

public TableSchema[] GetTables(string connectionString, DatabaseSchema database)
        {
            List<TableSchema> list = new List<TableSchema>();
            using (NpgsqlConnection npgsqlConnection = new NpgsqlConnection(connectionString))
            {
                npgsqlConnection.Open();
                using (NpgsqlCommand npgsqlCommand = new NpgsqlCommand("select tablename, tableowner,obj_description(relfilenode,'pg_class') as pg_description from pg_catalog.pg_tables as t left join pg_catalog.pg_class as c on t.tablename = c.relname where t.schemaname = 'public' order by t.tablename", npgsqlConnection))
                {
                    using (NpgsqlDataReader npgsqlDataReader = npgsqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
                    {
                        while (npgsqlDataReader.Read())
                        {
                            if (npgsqlDataReader.GetString(0).ToUpper() != "CODESMITH_EXTENDED_PROPERTIES")
                            {
                                list.Add(new TableSchema(database, npgsqlDataReader.GetString(0), npgsqlDataReader.GetString(1), DateTime.MinValue,new ExtendedProperty[]{
                                new ExtendedProperty("CS_Description", npgsqlDataReader.GetString(2) ?? string.Empty, DbType.String, PropertyStateEnum.ReadOnly)
                                }));
                            }
                        }
                    }
                }
            }
            return list.ToArray();
        }

        修改前的源碼與修改后的源碼主要有2個區別：增加了查詢表描述的字段、添加擴展屬性CS_Description這個屬性是關鍵將可以通過TableSchema.Description讀取表描述信息，這里存在一個問題，第二個參數不能為null，如果為null需要轉換為空串。

     2、修復讀取列信息的bug

      

     修改前的代碼

public ColumnSchema[] GetTableColumns(string connectionString, TableSchema table)
{
    List<ColumnSchema> list = new List<ColumnSchema>();
    using (NpgsqlConnection npgsqlConnection = new NpgsqlConnection(connectionString))
    {
        npgsqlConnection.Open();
        string text = string.Format("select column_name, is_nullable, character_maximum_length, numeric_precision, numeric_scale, data_type, udt_name from information_schema.columns where table_schema = 'public' and table_name='{0}'", table.Name);
        using (NpgsqlCommand npgsqlCommand = new NpgsqlCommand(text, npgsqlConnection))
        {
            using (NpgsqlDataReader npgsqlDataReader = npgsqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
            {
                while (npgsqlDataReader.Read())
                {
                    bool allowDBNull = npgsqlDataReader.IsDBNull(1) || npgsqlDataReader.GetString(1) == "YES";
                    byte precision = (byte)(npgsqlDataReader.IsDBNull(3) ? 0 : npgsqlDataReader.GetInt32(3));
                    int size = npgsqlDataReader.IsDBNull(2) ? 0 : npgsqlDataReader.GetInt32(2);
                    int scale = npgsqlDataReader.IsDBNull(4) ? 0 : npgsqlDataReader.GetInt32(4);
                    string name = npgsqlDataReader.IsDBNull(0) ? string.Empty : npgsqlDataReader.GetString(0);
                    string text2 = npgsqlDataReader.IsDBNull(5) ? string.Empty : npgsqlDataReader.GetString(5);
                    string type = npgsqlDataReader.IsDBNull(6) ? string.Empty : npgsqlDataReader.GetString(6);
                    list.Add(new ColumnSchema(table, name, PostgreSQLSchemaProvider.GetDbType(type), text2, size, precision, scale, allowDBNull, new ExtendedProperty[]
                    {
                        new ExtendedProperty("NpgsqlDbType", PostgreSQLSchemaProvider.GetNativeDbType(text2), DbType.String)
                    }));
                }
                if (!npgsqlDataReader.IsClosed)
                {
                    npgsqlDataReader.Close();
                }
            }
        }
        if (npgsqlConnection.State != ConnectionState.Closed)
        {
            npgsqlConnection.Close();
        }
    }
    return list.ToArray();
}

     修改后的代碼

public ColumnSchema[] GetTableColumns(string connectionString, TableSchema table)
        {
            List<ColumnSchema> list = new List<ColumnSchema>();
            using (NpgsqlConnection npgsqlConnection = new NpgsqlConnection(connectionString))
            {
                npgsqlConnection.Open();
                string text = string.Format("select column_name, is_nullable, character_maximum_length, numeric_precision, numeric_scale, data_type, udt_name,col_description(b.attrelid,b.attnum) as pg_description from information_schema.columns as a join pg_attribute as b on a.column_name=b.attname join pg_class as c on a.table_name=c.relname and b.attrelid = c.oid where b.attnum>0 and a.table_schema = 'public' and a.table_name='{0}'", table.Name);
                using (NpgsqlCommand npgsqlCommand = new NpgsqlCommand(text, npgsqlConnection))
                {
                    using (NpgsqlDataReader npgsqlDataReader = npgsqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
                    {
                        while (npgsqlDataReader.Read())
                        {
                            bool allowDBNull = npgsqlDataReader.IsDBNull(1) || npgsqlDataReader.GetString(1) == "YES";
                            byte precision = (byte)(npgsqlDataReader.IsDBNull(3) ? 0 : npgsqlDataReader.GetInt32(3));
                            int size = npgsqlDataReader.IsDBNull(2) ? 0 : npgsqlDataReader.GetInt32(2);
                            int scale = npgsqlDataReader.IsDBNull(4) ? 0 : npgsqlDataReader.GetInt32(4);
                            string name = npgsqlDataReader.IsDBNull(0) ? string.Empty : npgsqlDataReader.GetString(0);
                            string text2 = npgsqlDataReader.IsDBNull(5) ? string.Empty : npgsqlDataReader.GetString(5);
                            string type = npgsqlDataReader.IsDBNull(6) ? string.Empty : npgsqlDataReader.GetString(6);
                            list.Add(new ColumnSchema(table, name, PostgreSQLSchemaProvider.GetDbType(type), text2, size, precision, scale, allowDBNull, new ExtendedProperty[]
                    {
                        new ExtendedProperty("NpgsqlDbType", PostgreSQLSchemaProvider.GetNativeDbType(text2), DbType.String),
                        new ExtendedProperty("CS_Description",npgsqlDataReader.GetString(7)?? string.Empty, DbType.String)
                    }));
                        }
                        if (!npgsqlDataReader.IsClosed)
                        {
                            npgsqlDataReader.Close();
                        }
                    }
                }
            }
            return list.ToArray();
        }

修改前的源碼與修改后的源碼主要有2個區別：增加了查詢表描述的字段、添加擴展屬性CS_Description這個屬性是關鍵將可以通過ColumnSchema.Description讀取表描述信息，這里存在一個問題，第二個參數不能為null，如果為null需要轉換為空串。

三、修復主鍵信息

     因為在頁面加載列時，同時會根據表屬性去加載列的主鍵，外鍵屬性。

        public TableKeySchema[] GetTableKeys(string connectionString, TableSchema table)
        {
            List<TableKeySchema> list = new List<TableKeySchema>();
            using (NpgsqlConnection npgsqlConnection = new NpgsqlConnection(connectionString))
            {
                npgsqlConnection.Open();
                string text = string.Format("SELECT constraint_name as constrname FROM information_schema.table_constraints WHERE table_name = '{0}' AND constraint_type = 'FOREIGN KEY' AND constraint_schema='public'", table.Name);
                using (NpgsqlCommand npgsqlCommand = new NpgsqlCommand(text, npgsqlConnection))
                {
                    string text2 = string.Format("SELECT px.conname as constrname, att.attname as colname, fore.relname as reftabname, fatt.attname as refcolname, CASE px.confupdtype WHEN 'a' THEN 'NO ACTION' WHEN 'r' THEN 'RESTRICT' WHEN 'c' THEN 'CASCADE' WHEN 'n' THEN 'SET NULL' WHEN 'd' THEN 'SET DEFAULT' END AS on_update, CASE px.confdeltype WHEN 'a' THEN 'NO ACTION' WHEN 'r' THEN 'RESTRICT' WHEN 'c' THEN 'CASCADE' WHEN 'n' THEN 'SET NULL' WHEN 'd' THEN 'SET DEFAULT' END AS on_delete, CASE px.contype WHEN 'p' THEN true WHEN 'f' THEN false END as IsPrimaryKey from pg_constraint px left join pg_class home on (home.oid = px.conrelid) left join pg_class fore on (fore.oid = px.confrelid) left join pg_attribute att on (att.attrelid = px.conrelid AND att.attnum = ANY(px.conkey)) left join pg_attribute fatt on (fatt.attrelid = px.confrelid AND fatt.attnum = ANY(px.confkey)) where (home.relname = '{0}') and px.contype = 'f' order by constrname", table.Name);
                    using (NpgsqlCommand npgsqlCommand2 = new NpgsqlCommand(text2, npgsqlConnection))
                    {
                        NpgsqlDataAdapter npgsqlDataAdapter = new NpgsqlDataAdapter(npgsqlCommand);
                        DataSet dataSet = new DataSet();
                        npgsqlDataAdapter.Fill(dataSet, "constraint");
                        npgsqlDataAdapter.SelectCommand = npgsqlCommand2;
                        npgsqlDataAdapter.Fill(dataSet, "keys");
                        if (dataSet.Tables[0].Rows.Count > 0)
                        {
                            dataSet.Relations.Add("Contraint_to_Keys", dataSet.Tables[0].Columns["constrname"], dataSet.Tables[1].Columns["constrname"]);
                            foreach (DataRow dataRow in dataSet.Tables[0].Rows)
                            {
                                string name = dataRow["constrname"].ToString();
                                DataRow[] childRows = dataRow.GetChildRows("Contraint_to_Keys");
                                string[] array = new string[childRows.Length];
                                string[] array2 = new string[childRows.Length];
                                string name2 = table.Name;
                                string primaryKeyTable = childRows[0]["reftabname"].ToString();
                                for (int i = 0; i < childRows.Length; i++)
                                {
                                    array2[i] = childRows[i]["colname"].ToString();
                                    array[i] = childRows[i]["refcolname"].ToString();
                                }
                                list.Add(new TableKeySchema(table.Database, name, array2, name2, array, primaryKeyTable));
                            }
                        }
                    }
                }
                string text3 = string.Format("SELECT px.conname as constrname FROM pg_constraint px left join pg_class fore on fore.oid = px.confrelid where fore.relname = '{0}'", table.Name);
                using (NpgsqlCommand npgsqlCommand3 = new NpgsqlCommand(text3, npgsqlConnection))
                {
                    string text4 = string.Format("SELECT px.conname as constrname, fatt.attname as colname, home.relname as reftabname, att.attname as refcolname, CASE px.confupdtype WHEN 'a' THEN 'NO ACTION' WHEN 'r' THEN 'RESTRICT' WHEN 'c' THEN 'CASCADE' WHEN 'n' THEN 'SET NULL' WHEN 'd' THEN 'SET DEFAULT' END AS on_update, CASE px.confdeltype WHEN 'a' THEN 'NO ACTION' WHEN 'r' THEN 'RESTRICT' WHEN 'c' THEN 'CASCADE' WHEN 'n' THEN 'SET NULL' WHEN 'd' THEN 'SET DEFAULT' END AS on_delete, CASE px.contype WHEN 'p' THEN true WHEN 'f' THEN false END as IsPrimaryKey from pg_constraint px left join pg_class home on (home.oid = px.conrelid) left join pg_class fore on (fore.oid = px.confrelid) left join pg_attribute att on (att.attrelid = px.conrelid AND att.attnum = ANY(px.conkey)) left join pg_attribute fatt on (fatt.attrelid = px.confrelid AND fatt.attnum = ANY(px.confkey)) where (fore.relname = '{0}') order by constrname", table.Name);
                    using (NpgsqlCommand npgsqlCommand4 = new NpgsqlCommand(text4, npgsqlConnection))
                    {
                        NpgsqlDataAdapter npgsqlDataAdapter2 = new NpgsqlDataAdapter();
                        DataSet dataSet2 = new DataSet();
                        npgsqlDataAdapter2.SelectCommand = npgsqlCommand3;
                        npgsqlDataAdapter2.Fill(dataSet2, "constraint");
                        npgsqlDataAdapter2.SelectCommand = npgsqlCommand4;
                        npgsqlDataAdapter2.Fill(dataSet2, "keys");
                        if (dataSet2.Tables[0].Rows.Count > 0)
                        {
                            dataSet2.Relations.Add("Contraint_to_Keys", dataSet2.Tables[0].Columns["constrname"], dataSet2.Tables[1].Columns["constrname"]);
                            foreach (DataRow dataRow2 in dataSet2.Tables[0].Rows)
                            {
                                string name3 = dataRow2["constrname"].ToString();
                                DataRow[] childRows2 = dataRow2.GetChildRows("Contraint_to_Keys");
                                string[] array3 = new string[childRows2.Length];
                                string[] array4 = new string[childRows2.Length];
                                string foreignKeyTable = childRows2[0]["reftabname"].ToString();
                                string name4 = table.Name;
                                for (int j = 0; j < childRows2.Length; j++)
                                {
                                    array4[j] = childRows2[j]["refcolname"].ToString();
                                    array3[j] = childRows2[j]["colname"].ToString();
                                }
                                list.Add(new TableKeySchema(table.Database, name3, array4, foreignKeyTable, array3, name4));
                            }
                        }
                    }
                }
            }
            return list.ToArray();
        }

        public PrimaryKeySchema GetTablePrimaryKey(string connectionString, TableSchema table)
        {
            PrimaryKeySchema result = null;
            DataSet ds = new DataSet();
            using (NpgsqlConnection npgsqlConnection = new NpgsqlConnection(connectionString))
            {
                npgsqlConnection.Open();
                string text = string.Format("select constraint_name from information_schema.table_constraints where constraint_schema='public' and table_name='{0}' and constraint_type='PRIMARY KEY'", table.Name);
                using (NpgsqlCommand npgsqlCommand = new NpgsqlCommand(text, npgsqlConnection))
                {
                    using (NpgsqlDataAdapter nda = new NpgsqlDataAdapter(npgsqlCommand))
                    {
                        nda.Fill(ds, "table_constraints");
                    }

                }

                string text2 = string.Format("select px.conname as ConstraintName, att.attname as ColumnName from pg_constraint px inner join pg_class home on (home.oid = px.conrelid) left join pg_attribute att on (att.attrelid = px.conrelid AND att.attnum = ANY(px.conkey)) where (home.relname = '{0}') and px.contype = 'p'", table.Name);


                using (NpgsqlCommand npgsqlCommand2 = new NpgsqlCommand(text2, npgsqlConnection))
                {
                    using (NpgsqlDataAdapter nda = new NpgsqlDataAdapter(npgsqlCommand2))
                    {
                        nda.Fill(ds, "pg_constraint");
                    }

                }
                foreach (DataRow item in ds.Tables["table_constraints"].Rows)
                {
                    List<string> list = new List<string>();
                    foreach (DataRow item2 in ds.Tables["pg_constraint"].Rows)
                    {
                        list.Add(item2.Field<string>("ColumnName"));
                    }
                    result = new PrimaryKeySchema(table, item.Field<string>("constraint_name"), list.ToArray());

                }

            }
            return result;
        }

 

將程序重新編譯，替換原來的DLL。完成

 

四、補丁包及源碼下載：

    需要的朋友資助1分的CSDN資源分，辛苦勞動的獎勵