Add JSON and Vector samples (#3687)

* Add JSON and Vector samples

* Add xml snippet tags to include samples in sql-docs

Author: apoorvdeshmukh

doc/samples/SqlJsonExample.cs

@@ -0,0 +1,276 @@
+// JSONConsoleApp: End-to-end demo of working with
+// SQL Server JSON datatype via Microsoft.Data.SqlClient
+//
+// Highlights:
+// - Creates a demo table with a JSON column
+// - Inserts JSON via string and via SqlJson
+// - Inserts JSON from a file
+// - Reads JSON back with GetString and GetSqlJson
+// - Demonstrates a stored procedure with a JSON OUTPUT parameter
+//
+// Requirements:
+// - SQL Server 2025 and above.
+// - Microsoft.Data.SqlClient (6.1.2 and above)
+//<Snippet1>
+using System.Data;
+using Microsoft.Data;
+using Microsoft.Data.SqlClient;
+using Microsoft.Data.SqlTypes;
+using System.Text.Json;
+
+class Program
+{
+    // NOTE: For production, prefer Encrypt=True and TrustServerCertificate=False with a valid cert.
+    private const string connString = @"Server=tcp:localhost;Database=Demo2;Integrated Security=True;Encrypt=true;TrustServerCertificate=true;";
+    private const string tableName = "jsonTab";
+    private const string createBody = "(Id INT IDENTITY(1,1) PRIMARY KEY, Data json NULL)";
+
+    static void Main(string[] args)
+    {
+        CreateTable(connString, tableName, createBody);
+
+        InsertJSONWithStr(connString);
+        InsertJSONWithSqlJson(connString);
+        InsertJSONFile(connString);
+        ReadJSONWithGetString(connString);
+        ReadJSONWithSqlJson(connString);
+        ReadJsonWithSPParam(connString);
+    }
+
+    #region Helper Methods to Create/Drop Table and stored procedures
+    public static void CreateSP(string connString, string spName, string spBody)
+    {
+        DropSP(connString, spName);
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            string spCreate = "CREATE PROCEDURE " + spName + spBody;
+            using (SqlCommand command = sqlConnection.CreateCommand())
+            {
+                command.CommandText = spCreate;
+                command.ExecuteNonQuery();
+            }
+        }
+    }
+
+    public static void DropSP(string connString, string spName)
+    {
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand cmd = new SqlCommand(string.Format("IF (OBJECT_ID('{0}') IS NOT NULL) \n DROP PROCEDURE {0}", spName), sqlConnection))
+            {
+                cmd.ExecuteNonQuery();
+            }
+        }
+    }
+
+    private static void CreateTable(string connString, string tableName, string createBody)
+    {
+        DropTable(connString, tableName);
+        string tableCreate = "CREATE TABLE [" + tableName + "]" + createBody;
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand command = sqlConnection.CreateCommand())
+            {
+                command.CommandText = tableCreate;
+                command.ExecuteNonQuery();
+            }
+        }
+    }
+
+    private static void DropTable(string connString, string tableName)
+    {
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand cmd = new SqlCommand(string.Format("IF (OBJECT_ID('{0}') IS NOT NULL) \n DROP TABLE {0}", tableName), sqlConnection))
+            {
+                cmd.ExecuteNonQuery();
+            }
+        }
+    }
+
+    #endregion
+
+    private static void ReadJsonWithSPParam(string connString)
+    {
+        Console.WriteLine("Reading JSON with Stored Procedure and Output Parameter");
+
+        // Create stored procedure for reading JSON value
+        string storedProcName = "GetJsonData";
+        string tableName = "jsonTab";
+        string createSP = $@"
+                @id int,
+                @jsonData json OUTPUT
+                AS
+                BEGIN
+                    SELECT @jsonData = (SELECT Data FROM {tableName} WHERE Id = @id)
+                END;";
+        CreateSP(connString, storedProcName, createSP);
+
+        using (SqlConnection connection = new SqlConnection(connString))
+        {
+            connection.Open();
+            string procName = "GetJsonData";
+
+            // Execute Stored Procedure
+            using (SqlCommand spCommand = new SqlCommand(procName, connection))
+            {
+                spCommand.CommandType = CommandType.StoredProcedure;
+                spCommand.Parameters.Add(new SqlParameter("@id", SqlDbType.Int) { Direction = ParameterDirection.Input, Value = 1 });
+
+                //Use SqlDbType.Json depending on the dotnet version or or SqlDbTypeExtensions.Json 
+                SqlParameter outputParam = new SqlParameter("@jsonData", SqlDbTypeExtensions.Json) { Direction = ParameterDirection.Output };
+                spCommand.Parameters.Add(outputParam);
+                spCommand.ExecuteNonQuery();
+                Console.WriteLine($"JSON Data from SP: {outputParam.Value}");
+            }
+        }
+    }
+
+    private static void ReadJSONWithSqlJson(string connString)
+    {
+        Console.WriteLine("Reading JSON into SqlJson");
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand command = new SqlCommand("SELECT Data FROM jsonTab", sqlConnection))
+            {
+                using (SqlDataReader reader = command.ExecuteReader())
+                {
+                    while (reader.Read())
+                    {
+                        if (!reader.IsDBNull(0))
+                        {
+                            //Read JSON with GetString
+                            var jsonData = reader.GetSqlJson(0);
+                            Console.WriteLine($"JSON Data: {jsonData}");
+                        }
+                        else
+                        {
+                            Console.WriteLine("JSON Data: NULL");
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private static void ReadJSONWithGetString(string connString)
+    {
+        Console.WriteLine("Reading JSON with GetString");
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand command = new SqlCommand("SELECT Data FROM jsonTab", sqlConnection))
+            {
+                using (SqlDataReader reader = command.ExecuteReader())
+                {
+                    while (reader.Read())
+                    {
+                        if (!reader.IsDBNull(0))
+                        {
+                            //Read JSON with GetString
+                            string jsonData = reader.GetString(0);
+                            Console.WriteLine($"JSON Data: {jsonData}");
+                        }
+                        else
+                        {
+                            Console.WriteLine("JSON Data: NULL");
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private static void InsertJSONFile(string connString)
+    {
+        Console.WriteLine("Inserting JSON File");
+        var dummyData = new
+        {
+            name = "Keith Johnson",
+            age = 36,
+            city = "Boston"
+        };
+
+        string jsonString = JsonSerializer.Serialize(dummyData, new JsonSerializerOptions { WriteIndented = true });
+        string jsonFile = "dummyData.json";
+        if (File.Exists(jsonFile))
+        {
+            File.Delete(jsonFile);
+        }
+        File.WriteAllText(jsonFile, jsonString);
+
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand command = new SqlCommand("INSERT INTO jsonTab (Data) VALUES (@jsonData)", sqlConnection))
+            {
+                SqlParameter jsonParam = new SqlParameter("@jsonData", SqlDbTypeExtensions.Json);
+                using (StreamReader jsonFileReader = File.OpenText(jsonFile))
+                {
+                    jsonParam.Value = jsonFileReader;
+                    command.Parameters.Add(jsonParam);
+                    command.ExecuteNonQuery();
+                }
+            }
+        }
+        if (File.Exists(jsonFile))
+        {
+            File.Delete(jsonFile);
+        }
+    }
+
+    private static void InsertJSONWithSqlJson(string connString)
+    {
+        Console.WriteLine("Inserting JSON with SqlJson");
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand command = new SqlCommand("INSERT INTO jsonTab (Data) VALUES (@jsonData)", sqlConnection))
+            {
+                //Insert non-null value with SqlJson
+                string jsonData = @"{ ""name"": ""Jane Smith"", ""age"": 25, ""city"": ""Los Angeles"" }";
+                SqlJson sqlJsonObj = new SqlJson(jsonData);
+                SqlParameter jsonParam = new SqlParameter("@jsonData", SqlDbTypeExtensions.Json) { Value = sqlJsonObj };
+                command.Parameters.Add(jsonParam);
+                command.ExecuteNonQuery();
+                command.Parameters.Clear();
+
+                //Insert null value with SqlJson
+                sqlJsonObj = new SqlJson();
+                jsonParam.Value = sqlJsonObj;
+                command.Parameters.Add(jsonParam);
+                command.ExecuteNonQuery();
+            }
+        }
+    }
+
+    private static void InsertJSONWithStr(string connString)
+    {
+        Console.WriteLine("Inserting JSON with string");
+        string insertQuery = "INSERT INTO jsonTab (Data) VALUES (@jsonData)";
+
+        using (SqlConnection sqlConnection = new SqlConnection(connString))
+        {
+            sqlConnection.Open();
+            using (SqlCommand command = new SqlCommand(insertQuery, sqlConnection))
+            {
+                //Insert non-null value
+                string jsonData = @"{ ""name"": ""John Doe"", ""age"": 30, ""city"": ""New York"" }";
+                command.Parameters.AddWithValue("@jsonData", jsonData);
+                command.ExecuteNonQuery();
+                command.Parameters.Clear();
+
+                //Insert null value
+                command.Parameters.AddWithValue("@jsonData", DBNull.Value);
+                command.ExecuteNonQuery();
+            }
+        }
+    }
+}
+//</Snippet1>
+