convert from SqlDataReader to JSON

Question

public string toJSON(SqlDataReader o)
{
    StringBuilder s = new StringBuilder();
    s.Append(\"[\");
    if (o.HasRows)
        while (o.Read())
            s.App         


        

Answer 1

Since SQL Server 2016, Microsoft embedded this feature with sql queries. You can achieve it by using FOR JSON keyword at the end of your queries.

select * from table_example where somecolumn = somecondition FOR JSON AUTO

for more details and example you can go through this official documents Format JSON Output Automatically with AUTO Mode (SQL Server)

Here is the C# code example from Microsoft to get JSON string from SQL queries.

var queryWithForJson = "SELECT ... FOR JSON";
var conn = new SqlConnection("");
var cmd = new SqlCommand(queryWithForJson, conn);
conn.Open();
var jsonResult = new StringBuilder();
var reader = cmd.ExecuteReader();
if (!reader.HasRows)
{
    jsonResult.Append("[]");
}
else
{
    while (reader.Read())
    {
        jsonResult.Append(reader.GetValue(0).ToString());
    }
}

Warning: This solution is only valid for SQL SERVER 2016 and higher.