使用 .net 程序操作数据库
=======================
除了使用SQL内核执行SQL语句直接操作数据库，使用最多的是使用用.net程序操作数据库：
+ ado.net 原生操作
+ 使用ORM框架，比如 Daper、EFCore、SqlSugar、FreeSQL等
## 初始化
```csharp
#!import "./Base.ipynb"

//共享
#r "nuget:Microsoft.Data.SqlClient"
#r "nuget:MySql.Data"
#r "nuget:Npgsql"
#r "nuget:Microsoft.Data.Sqlite"
#r "nuget:DuckDB.NET.Data.Full"

#r "nuget:Dapper"

#r "nuget:Microsoft.EntityFrameworkCore"
#r "nuget:Microsoft.EntityFrameworkCore.SqlServer"
#r "nuget:Microsoft.EntityFrameworkCore.Sqlite"
#r "nuget:Npgsql.EntityFrameworkCore.PostgreSQL"
#r "nuget:MySql.EntityFrameworkCore"
//#r "nuget:Pomelo.EntityFrameworkCore.MySql"
#r "nuget:MongoDB.EntityFrameworkCore"

global using System.Text.Json;
global using System.Text.Json.Schema;
global using System.Text.Json.Serialization;

global using System.Data;
global using System.Data.Common;
global using System.Data.SqlTypes;
global using System.Data.SqlClient;
//global using System.Data.OracleClient;

global using Microsoft.Data.SqlClient;
global using Microsoft.Data.SqlClient.Server;

global using MySql.Data;
global using MySql.Data.Types;
global using MySql.Data.MySqlClient;

global using Microsoft.Data.Sqlite;

global using DuckDB.NET.Data;
global using DuckDB.NET.Data.DataChunk;

global using Dapper;

global using Npgsql;
global using Npgsql.Schema;
global using Npgsql.PostgresTypes;
global using Npgsql.TypeMapping;
global using Npgsql.Util;
global using Npgsql.NameTranslation;
global using Npgsql.BackendMessages;


global using Microsoft.EntityFrameworkCore;
global using Microsoft.EntityFrameworkCore.SqlServer;
global using Microsoft.EntityFrameworkCore.Sqlite;
global using Npgsql.EntityFrameworkCore.PostgreSQL;
global using MySql.EntityFrameworkCore;
global using MongoDB.EntityFrameworkCore;

//共享方法
public static List<Student> DatatableToStudent(DataTable studentTable)
{
    var students = new List<Student>();
    if(studentTable == null)
    {
        return students;
    }

    if(studentTable.Columns.Count ==0)
    {
        return students;
    }

    if(studentTable.Rows.Count <=0)
    {
        return students;
    }

    foreach(DataRow row in studentTable.Rows)
    {
        var student = new Student()
        {
            Id = (int)row["Id"],
            Name = row["Name"] == DBNull.Value ? "" : (string)row["Name"].ToString(),
            Age = row["Age"] == DBNull.Value ? 0 : (int)row["Age"]
        };

        students.Add(student);
    }

    return students;
}
```
## 使用 ADO.NET
### SQL Server 数据库(2019为例)
```csharp
//Ado.Net 操作SQL Server
{
    DataSet ds = new DataSet();

    using(var mssqlConnection = new SqlConnection(SharedDbConnect.MsSqlConnectionString))
    {
        mssqlConnection.Open();

        var querySql = "select * FROM student where age >@age;";
        SqlParameter[] parameters = new SqlParameter[]
        {
            new SqlParameter()
            {
                ParameterName = "age",
                SqlDbType = SqlDbType.Int,
                Value = 50,
                Direction = ParameterDirection.Input,
                Size = 4,
                DbType = DbType.Int32,
                IsNullable = false,
            }
        };
        var command = new SqlCommand(querySql, mssqlConnection);
        command.Parameters.AddRange(parameters);

        var adapter =  new SqlDataAdapter(command);
        adapter.Fill(ds);

        mssqlConnection.Close();
        mssqlConnection.Dispose();
    }

    var students = DatatableToStudent(ds.Tables[0]);

    Console.WriteLine($"查询到: {students.Count()} 行数据");
    var jsonText = System.Text.Json.JsonSerializer.Serialize(students.Take<Student>(2), new System.Text.Json.JsonSerializerOptions()
    {
        Encoder = System.Text.Encodings.Web.JavaScriptEncoder.Create(System.Text.Unicode.UnicodeRanges.All),
        WriteIndented = false,
    });

    Console.WriteLine($"前2行：{jsonText}");
}
```
### MySQL
```csharp
//Ado.Net 操作MySQL
{
    //查询数据
    DataSet ds = new DataSet();

    using(var sqlConnection = new MySqlConnection(SharedDbConnect.MySQLConnectionString))
    {
        sqlConnection.Open();

        var querySql = "SELECT * FROM `Student` LIMIT 2;";
        var command = new MySqlCommand(querySql, sqlConnection);

        var adapter =  new MySqlDataAdapter(command);
        adapter.Fill(ds);

        sqlConnection.Close();
        sqlConnection.Dispose();
    }

    //输出数据
    var dt = ds.Tables[0];
    int padRightCount = 15;

    //输出列
    List<string> columnNames = new List<string>(100);
    foreach(DataColumn c in dt.Columns)
    {
        columnNames.Add(c.ColumnName.PadRight(padRightCount));
    }

    Console.WriteLine(string.Join("", columnNames));

    //输出数据
    foreach(DataRow row in dt.Rows)
    {
        List<string> rowItemValues = new List<string>(100);

        for(int i=0; i<columnNames.Count(); i++)
        {
            var valueText = row[i] == DBNull.Value? "null" : row[i].ToString();
            rowItemValues.Add(valueText.PadRight(padRightCount));
        }

        Console.WriteLine(string.Join("",rowItemValues));
    }
}
```
### PostgreSQL
```csharp
//Ado.Net 操作PostgreSQL
{
    //查询数据
    DataSet ds = new DataSet();
    using(var sqlConnection = new NpgsqlConnection(SharedDbConnect.PSQLConnectionString))
    {
        sqlConnection.Open();
        
        var querySql = 
        """
            SELECT * FROM "Student" LIMIT 5;
        """;
        var command = new NpgsqlCommand(querySql, sqlConnection);

        var adapter =  new NpgsqlDataAdapter(command);
        adapter.Fill(ds);

        sqlConnection.Close();
        sqlConnection.Dispose();
    }

    //输出数据
    var dt = ds.Tables[0];
    int padRightCount = 15;

    //输出列
    List<string> columnNames = new List<string>(100);
    foreach(DataColumn c in dt.Columns)
    {
        columnNames.Add(c.ColumnName.PadRight(padRightCount));
    }

    Console.WriteLine(string.Join("", columnNames));

    //输出数据
    foreach(DataRow row in dt.Rows)
    {
        List<string> rowItemValues = new List<string>(100);

        for(int i=0; i<columnNames.Count(); i++)
        {
            var valueText = row[i] == DBNull.Value? "null" : row[i].ToString();
            rowItemValues.Add(valueText.PadRight(padRightCount));
        }

        Console.WriteLine(string.Join("",rowItemValues));
    }
}
```
```csharp
//Ado.Net 操作PostgreSQL: 客户端官方用法(异步)
{
    //查询数据
    DataSet ds = new DataSet();
    int padRightCount = 15;
   
    await using var dataSource = NpgsqlDataSource.Create(SharedDbConnect.PSQLConnectionString);

    await using (var cmd = dataSource.CreateCommand("SELECT * FROM \"Student\" LIMIT 5;"))

    await using (var reader = await cmd.ExecuteReaderAsync())
    {
        //输出列名
         List<string> columnNames = reader.GetColumnSchema().Select(c => c.ColumnName.PadRight(padRightCount)).ToList();
        Console.WriteLine(string.Join("", columnNames));

        //循环输出行数据
        while (await reader.ReadAsync())
        {
            List<string> rowItemValues = new List<string>(100);
            for(int i=0; i<columnNames.Count(); i++)
            {
                var valueText = reader.GetFieldValue<object>(i).ToString();
                rowItemValues.Add(valueText.PadRight(padRightCount));
            }

            Console.WriteLine(string.Join("",rowItemValues));
        }
    }
}
```
### SQLite
```csharp
//Ado.Net 操作SQLite
{
    //查询数据
    DataSet ds = new DataSet();
    int padRightCount = 15;

    using(var sqlConnection = new SqliteConnection(SharedDbConnect.SQLiteConnectionString))
    {
        sqlConnection.Open();
        
        var querySql = 
        """
            SELECT * FROM Student LIMIT 5;
        """;
        var cmd = sqlConnection.CreateCommand();
        cmd.CommandType = CommandType.Text;
        cmd.CommandText = querySql;

        using (var reader = await cmd.ExecuteReaderAsync())
        {
            //输出列名
            List<string> columnNames = reader.GetColumnSchema().Select(c => c.ColumnName.PadRight(padRightCount)).ToList();
            Console.WriteLine(string.Join("", columnNames));

            //循环输出行数据
            while (await reader.ReadAsync())
            {
                List<string> rowItemValues = new List<string>(100);
                for(int i=0; i<columnNames.Count(); i++)
                {
                    var valueText = reader.GetFieldValue<object>(i).ToString();
                    rowItemValues.Add(valueText.PadRight(padRightCount));
                }

                Console.WriteLine(string.Join("",rowItemValues));
            }
        }

        sqlConnection.Close();
        sqlConnection.Dispose();
    }
}
```
### DuckDB
```csharp
//Ado.Net 操作DuckDB数据库
{
    int padRightCount = 15;

    using(var sqlConnection = new DuckDBConnection(SharedDbConnect.DuckDBConnectionString))
    {
        sqlConnection.Open();
        //1、创建表
        var createTableSql = 
        """
        CREATE TABLE Student 
        (
            Id INTEGER,
            Name TEXT,
            Age INTEGER
        );
        """;

        var createCommand = sqlConnection.CreateCommand();
        createCommand.CommandType = CommandType.Text;
        createCommand.CommandText = createTableSql;

        var createCount = createCommand.ExecuteNonQuery();
        //Console.WriteLine($"{createCount}");

        //2、插入示例数据
        var insertSql = 
        """
        INSERT INTO Student VALUES (1, '张三', 10), (2, '李四', 33), (3, '王五', 66);
        """;

        var insertCommand = sqlConnection.CreateCommand();
        insertCommand.CommandType = CommandType.Text;
        insertCommand.CommandText = insertSql;

        var insertCount = insertCommand.ExecuteNonQuery();
        //Console.WriteLine($"{insertCount}");

        //3、查询数据
        var querySql = 
        """
            SELECT * FROM Student ORDER BY Age
        """;
        var queryCommand = sqlConnection.CreateCommand();
        queryCommand.CommandType = CommandType.Text;
        queryCommand.CommandText = querySql;

        using (var reader = await queryCommand.ExecuteReaderAsync())
        {
            //输出列名
            List<string> columnNames = reader.GetColumnSchema().Select(c => c.ColumnName.PadRight(padRightCount)).ToList();
            Console.WriteLine(string.Join("", columnNames));

            //循环输出行数据
            while (await reader.ReadAsync())
            {
                List<string> rowItemValues = new List<string>(100);
                for(int i=0; i<columnNames.Count(); i++)
                {
                    var valueText = reader.GetValue(i).ToString();
                    rowItemValues.Add(valueText.PadRight(padRightCount));
                }

                Console.WriteLine(string.Join("",rowItemValues));
            }
        }

        sqlConnection.Close();
        sqlConnection.Dispose();
    }
}
```
## 使用 Dapper
### Dapper 操作 SQL Server 2019
```csharp
//Dapper 操作SQL Server
{
    using(var mssqlConnection = new SqlConnection(SharedDbConnect.MsSqlConnectionString))
    {
        var querySql = "select * FROM student;";
        var students = mssqlConnection.Query<Student>(querySql).Take(2);
         var jsonText = System.Text.Json.JsonSerializer.Serialize(students, new System.Text.Json.JsonSerializerOptions()
        {
            Encoder = System.Text.Encodings.Web.JavaScriptEncoder.Create(System.Text.Unicode.UnicodeRanges.All),
            WriteIndented = false,
        });

        Console.WriteLine(jsonText);
    }
}
```
###  Dapper 操作 MySQL
```csharp
//Dapper 操作MySQL
{
    using(var dbConnection = new MySqlConnection(SharedDbConnect.MySQLConnectionString))
    {
        var querySql = "SELECT * FROM `Student` LIMIT @top;";
        var students = dbConnection.Query<Student>(querySql, new {top=2});

        var jsonText = System.Text.Json.JsonSerializer.Serialize(students, new System.Text.Json.JsonSerializerOptions()
        {
            Encoder = System.Text.Encodings.Web.JavaScriptEncoder.Create(System.Text.Unicode.UnicodeRanges.All),
            WriteIndented = false,
        });

        Console.WriteLine(jsonText);
    }
}
```
###  Dapper 操作 PostgreSQL
```csharp
//Dapper 操作 PSQL
{
    using(var dbConnection = new NpgsqlConnection(SharedDbConnect.PSQLConnectionString))
    {
        var querySql = "SELECT * FROM \"Student\" Where \"Age\" > @Age LIMIT @Top;";
        var students = dbConnection.Query<Student>(querySql, new {Age = 50, top = 2});

        var jsonText = System.Text.Json.JsonSerializer.Serialize(students, new System.Text.Json.JsonSerializerOptions()
        {
            Encoder = System.Text.Encodings.Web.JavaScriptEncoder.Create(System.Text.Unicode.UnicodeRanges.All),
            WriteIndented = false,
        });

        Console.WriteLine(jsonText);
    }
}
```
## 使用 EF Core
```csharp
//共享
/// <summary>
///  SQL Server DbContext
/// </summary>
public class StudyDbContext: DbContext
{
    public StudyDbContext(DbContextOptions<StudyDbContext> option):base(option)
    {

    }

    public DbSet<Student> Student {get; set;}

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
        if(!optionsBuilder.IsConfigured)
        {
                Console.WriteLine("没有设置");
        }
    }
}
```
### EF Core 操作 SQL Server
 
```csharp
{   //EF Core SQL Server
    var builder = new DbContextOptionsBuilder<StudyDbContext>();
    builder.UseSqlServer(SharedDbConnect.MsSqlConnectionString);

    var dbContext = new StudyDbContext(builder.Options);
    var students = dbContext.Student.Where(s => s.Age> 95).ToList();
    students.Display();
}
```
### EF Core 查询 MySQL
```csharp
{   //EF Core MySQL
    var builder = new DbContextOptionsBuilder<StudyDbContext>();
    builder.UseMySQL(SharedDbConnect.MySQLConnectionString);

    var dbContext = new StudyDbContext(builder.Options);
    var students = dbContext.Student.Where(s => s.Age> 95).ToList();
    students.Display();
}
```
### EFCore PostgreSQL
```csharp
{   
    var builder = new DbContextOptionsBuilder<StudyDbContext>();
    builder.UseNpgsql(SharedDbConnect.PSQLConnectionString);

    var dbContext = new StudyDbContext(builder.Options);
    var students = dbContext.Student.Where(s => s.Age> 95).ToList();
    students.Display();
}
```