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How can i compare an array with sql query in c# code?

How can I compare an array with a SQL query in C#?
I have tried below code to resolve my problem but it was not worked.
In the below code data is the name of array which holds some types of data.
DataTable dt = context.getData("Select * from emp_detail where EState = any(" +data+ ")", CommandType.Text);

You can serialize the data array into a properly formatted string and change select command to something like that:
Select * from emp_detail where EState in ('a', 'b', ...)
This solution is only suitable for arrays with few items.

I think you could do this to get a list of strings to compare with:
using System.Linq;
namespace ExampleNamespase
{
public class SimpleClass
{
private class TypeExample
{
public string Property { get; }
}
private void CompareData(TypeExample[] exampleArray)
{
var items = string.Join(", ", exampleArray.Select(t => t.Property));
var sql = $"Select * from emp_detail where EState in ({items}) ";
}
}
}
Or so if you are using a simple list of strings:
private void CompareData(string[] exampleArray)
{
var items = string.Join(", ", exampleArray);
var sql = $"Select * from emp_detail where EState in ({items}) ";
}
To prevent injections, use the Dapper library:
using System.Data;
using Dapper;
namespace ExampleNamespase
{
public class SimpleClass
{
private void CompareData(string[] exampleArray, IDbConnection connection)
{
var sql = "Select * from emp_detail where EState in #items ";
var result = connection.Query<YourTypeClass>(sql, new { items = exampleArray });
}
}
}
Explanation:
The first example uses the Linq library to retrieve the properties of an object using the Select method, and the string.Join method to concatenate the resulting list into a comma-separated string.
The second example demonstrates the same approach, only with an array of strings, the same string.Join method is used to join.
In the third example, the Dapper library is used to execute the request, I believe that this method should be preferred, since helps to avoid SQL injection, and also simplifies the work with the database. To execute a query, we can pass a list of objects with which we want to compare values ​​in the database, and Dapper will be able to handle this itself. We just need to define variables with the # symbol in the request, and pass the object for processing, which will have attributes with the same names.
P.S. I apologize for my English))
Upd:
Try this:
private void CampareData(string[] exampleArray, IDbConnection connection)
{
var clearItems = exampleArray.Select(s => $"'{s}'").ToArray();
var sql = "Select * from emp_detail where EState in #items ";
var result = connection.Query<YourTypeClass>(sql, new { items = clearItems });
}
In this variant, we will wrap each item in quotes that are used by sql, and the query should contain something like: ... in ('item1', 'item2' ...)

DapperExtensions: Add "insert ... update on duplicate key"

Now I'm using Dapper + Dapper.Extensions. And yes, it's easy and awesome. But I faced with a problem: Dapper.Extensions has only Insert command and not InsertUpdateOnDUplicateKey. I want to add such method but I don't see good way to do it:
I want to make this method generic like Insert
I can't get cached list of properties for particular type because I don't want to use reflection directly to build raw sql
Possible way here to fork it on github but I want to make it in my project only. Does anybody know how to extend it? I understand this feature ("insert ... update on duplicate key") is supported only in MySQL. But I can't find extension points in DapperExtensions to add this functionality outside.
Update: this is my fork https://github.com/MaximTkachenko/Dapper-Extensions/commits/master

This piece of code has helped me enormously in MySQL -related projects, I definitely owe you one.
I do a lot of database-related development on both MySQL and MS SQL. I also try to share as much code as possible between my projects.
MS SQL has no direct equivalent for "ON DUPLICATE KEY UPDATE", so I was previously unable to use this extension when working with MS SQL.
While migrating a web application (that leans heavily on this Dapper.Extensions tweak) from MySQL to MS SQL, I finally decided to do something about it.
This code uses the "IF EXISTS => UPDATE ELSE INSERT" approach that basically does the same as "ON DUPLICATE KEY UPDATE" on MySQL.
Please note: the snippet assumes that you are taking care of transactions outside this method. Alternatively you could append "BEGIN TRAN" to the beginning and "COMMIT" to the end of the generated sql string.
public static class SqlGeneratorExt
{
public static string InsertUpdateOnDuplicateKey(this ISqlGenerator generator, IClassMapper classMap, bool hasIdentityKeyWithValue = false)
{
var columns = classMap.Properties.Where(p => !(p.Ignored || p.IsReadOnly || (p.KeyType == KeyType.Identity && !hasIdentityKeyWithValue))).ToList();
var keys = columns.Where(c => c.KeyType != KeyType.NotAKey).Select(p => $"{generator.GetColumnName(classMap, p, false)}=#{p.Name}");
var nonkeycolumns = classMap.Properties.Where(p => !(p.Ignored || p.IsReadOnly) && p.KeyType == KeyType.NotAKey).ToList();
if (!columns.Any())
{
throw new ArgumentException("No columns were mapped.");
}
var tablename = generator.GetTableName(classMap);
var columnNames = columns.Select(p => generator.GetColumnName(classMap, p, false));
var parameters = columns.Select(p => generator.Configuration.Dialect.ParameterPrefix + p.Name);
var valuesSetters = nonkeycolumns.Select(p => $"{generator.GetColumnName(classMap, p, false)}=#{p.Name}").ToList();
var where = keys.AppendStrings(seperator: " and ");
var sqlbuilder = new StringBuilder();
sqlbuilder.AppendLine($"IF EXISTS (select * from {tablename} WITH (UPDLOCK, HOLDLOCK) WHERE ({where})) ");
sqlbuilder.AppendLine(valuesSetters.Any() ? $"UPDATE {tablename} SET {valuesSetters.AppendStrings()} WHERE ({where}) " : "SELECT 0 ");
sqlbuilder.AppendLine($"ELSE INSERT INTO {tablename} ({columnNames.AppendStrings()}) VALUES ({parameters.AppendStrings()}) ");
return sqlbuilder.ToString();
}
}

Actually I closed my pull request and remove my fork because:
I see some open pull requests created in 2014
I found a way "inject" my code in Dapper.Extensions.
I remind my problem: I want to create more generic queries for Dapper.Extensions. It means I need to have access to mapping cache for entities, SqlGenerator etc. So here is my way. I want to add ability to make INSERT .. UPDATE ON DUPLICATE KEY for MySQL. I created extension method for ISqlGenerator
public static class SqlGeneratorExt
{
public static string InsertUpdateOnDuplicateKey(this ISqlGenerator generator, IClassMapper classMap)
{
var columns = classMap.Properties.Where(p => !(p.Ignored || p.IsReadOnly || p.KeyType == KeyType.Identity));
if (!columns.Any())
{
throw new ArgumentException("No columns were mapped.");
}
var columnNames = columns.Select(p => generator.GetColumnName(classMap, p, false));
var parameters = columns.Select(p => generator.Configuration.Dialect.ParameterPrefix + p.Name);
var valuesSetters = columns.Select(p => string.Format("{0}=VALUES({1})", generator.GetColumnName(classMap, p, false), p.Name));
string sql = string.Format("INSERT INTO {0} ({1}) VALUES ({2}) ON DUPLICATE KEY UPDATE {3}",
generator.GetTableName(classMap),
columnNames.AppendStrings(),
parameters.AppendStrings(),
valuesSetters.AppendStrings());
return sql;
}
}
One more extension method for IDapperImplementor
public static class DapperImplementorExt
{
public static void InsertUpdateOnDuplicateKey<T>(this IDapperImplementor implementor, IDbConnection connection, IEnumerable<T> entities, int? commandTimeout = null) where T : class
{
IClassMapper classMap = implementor.SqlGenerator.Configuration.GetMap<T>();
var properties = classMap.Properties.Where(p => p.KeyType != KeyType.NotAKey);
string emptyGuidString = Guid.Empty.ToString();
foreach (var e in entities)
{
foreach (var column in properties)
{
if (column.KeyType == KeyType.Guid)
{
object value = column.PropertyInfo.GetValue(e, null);
string stringValue = value.ToString();
if (!string.IsNullOrEmpty(stringValue) && stringValue != emptyGuidString)
{
continue;
}
Guid comb = implementor.SqlGenerator.Configuration.GetNextGuid();
column.PropertyInfo.SetValue(e, comb, null);
}
}
}
string sql = implementor.SqlGenerator.InsertUpdateOnDuplicateKey(classMap);
connection.Execute(sql, entities, null, commandTimeout, CommandType.Text);
}
}
Now I can create new class derived from Database class to use my own sql
public class Db : Database
{
private readonly IDapperImplementor _dapperIml;
public Db(IDbConnection connection, ISqlGenerator sqlGenerator) : base(connection, sqlGenerator)
{
_dapperIml = new DapperImplementor(sqlGenerator);
}
public void InsertUpdateOnDuplicateKey<T>(IEnumerable<T> entities, int? commandTimeout) where T : class
{
_dapperIml.InsertUpdateOnDuplicateKey(Connection, entities, commandTimeout);
}
}
Yeah, it's required to create another DapperImplementor instance because DapperImplementor instance from base class is private :(. So now I can use my Db class to call my own generic sql queries and native queries from Dapper.Extension. Examples of usage Database class instead of IDbConnection extensions can be found here.

How would you match a record from a select statement against a string in c#?

I'm trying to create a statement to check data from a foxpro database against a string in c#
however I can't seem to get it working, would using parameterised queries here help to achieve what I'm trying to do?
string PROPCODE = "IMPORT_" + ID;
string leadtenant = clcodet;
using (OleDbCommand tenantpopulation = new OleDbCommand(#"SELECT
CLCODE,
CLCODEDESC
FROM CLIENT WHERE PROPCODET = " + PROPCODE, importConnection))
{
string tenants = "";
if (#"CLCODE" = leadtenant)
{
if (tenants != String.Empty)
{
//do something
}
}
}
To Clarify, i want to check whether CLCODE, called from tenantpopulation, matches leadtenant, defined elsewhere in the code

As others already noted using parameters is the way to go (not only in VFP but any SQL database). They are not only for preventing SQL injection attacks, using parameters the drivers take care of converting into correct string, adding/removing braces, quotes etc.
string PROPCODE = "IMPORT_" + ID;
string leadtenant = clcodet;
using (OleDbCommand tenantpopulation = new OleDbCommand(#"SELECT
CLCODE
FROM CLIENT WHERE PROPCODET = ?", importConnection))
{
tenantpopulation.Parameters.AddWithValue("p", PROPCODE);
// rest of code seem to be meaningless
// and I didn't see any code where you run your query
// depending on your requirement, I assume PROPCODET is a primary key?
// if so then you to do the check you only need to return the CLCODE
// with ExecuteScalar:
importConnection.Open();
var clcode = (string)tenantpopulation.ExecuteScalar();
importConnection.Close();
string tenants = "";
// in C# equality check is done with == NOT = (assingment)
if (clcode == leadtenant)
{
// tenants is always String.Empty here
if (tenants != String.Empty)
{
//do something
}
}
}
PS: Have you ever thought, using Tom Brother's LinqToVFP from codeplex? With Linq, you don't need to know these SQL dialects much and instead you use Object query (and intellisense).

how to convert int to string in Linq to entities

My Db column in a string (varchar) and i need to assign it to a int value.
I am using linq to query.Though the code compiles am getting an error at the run time .
Thanks in advance.
PFB my query :
var vlauesCap = from plan in entities.PA_RTM_CAP_Group
select new Business.PartnerProfile.LookUp
{
Id =Convert.ToInt32(plan.cap_group_code),
//(Int32)plan.cap_group_code,
Value = plan.cap_group_name
};
return vlauesCap.ToList();

The EF provider does not know how to translate Convert.ToInt() into SQL it can run against the database. Instead of doing the conversion on the server, you can pull the results back and do the conversion using linq to objects:
// the ToList() here causes the query to be executed on the server and
// the results are returned in a list of anonymous objects
var results = (from plan in entities.PA_RTM_CAP_Group
select new
{
Code = plan.cap_group_code,
Name = plan.cap_group_name
}).ToList();
// the conversion can now be done here using Linq to Objects
var vlauesCap = from r in results
select new Business.PartnerProfile.LookUp
{
Id = Convert.ToInt32(r.Code),
Value = r.Name
};
return vlauesCap.ToList();

You can't do this directly, what you can do is declare a private variable to handle your "mapped" value, and expose the unmapped property...
[Column(Name = "cap_group_code", Storage = "m_cap_group_code")]
private string m_cap_group_code;
public int cap_group_code {
get
{
return Int32.Parse(m_cap_group_code);
}
set
{
m_cap_group_code = value.ToString();
}
}

Try this:
var vlauesCap = from plan in entities.PA_RTM_CAP_Group
select new Business.PartnerProfile.LookUp
{
Id =Convert.ToInt32(plan.cap_group_code),
Convert.ToInt32(plan.cap_group_code),
Value = plan.cap_group_name
};
return vlauesCap.ToList();

Why aren't you using casting for such a purpose, which is a more effective way of achieving this.
Just replace Convert.ToInt32(plan.cap_group_code) with (int)plan.cap_group_code
Do remember, there should be a value in the string and is int, else it will show Exception. If you are not sure about it, then you can further expand the casting to use null coalesciting operator

Regex Replace to assist Orderby in LINQ

I'm using LINQ to SQL to pull records from a database, sort them by a string field, then perform some other work on them. Unfortunately the Name field that I'm sorting by comes out of the database like this
Name
ADAPT1
ADAPT10
ADAPT11
...
ADAPT2
ADAPT3
I'd like to sort the Name field in numerical order. Right now I'm using the Regex object to replace "ADAPT1" with "ADAPT01", etc. I then sort the records again using another LINQ query. The code I have for this looks like
var adaptationsUnsorted = from aun in dbContext.Adaptations
where aun.EventID == iep.EventID
select new Adaptation
{
StudentID = aun.StudentID,
EventID = aun.EventID,
Name = Regex.Replace(aun.Name,
#"ADAPT([0-9])$", #"ADAPT0$1"),
Value = aun.Value
};
var adaptationsSorted = from ast in adaptationsUnsorted
orderby ast.Name
select ast;
foreach(Adaptation adaptation in adaptationsSorted)
{
// do real work
}
The problem I have is that the foreach loop throws the exception
System.NotSupportedException was unhandled
Message="Method 'System.String Replace(System.String, System.String,
System.String)' has no supported translation to SQL."
Source="System.Data.Linq"
I'm also wondering if there's a cleaner way to do this with just one LINQ query. Any suggestions would be appreciated.

Force the hydration of the elements by enumerating the query (call ToList). From that point on, your operations will be against in-memory objects and those operations will not be translated into SQL.
List<Adaptation> result =
dbContext.Adaptation
.Where(aun => aun.EventID = iep.EventID)
.ToList();
result.ForEach(aun =>
aun.Name = Regex.Replace(aun.Name,
#"ADAPT([0-9])$", #"ADAPT0$1")
);
result = result.OrderBy(aun => aun.Name).ToList();

Implement a IComparer<string> with your logic:
var adaptationsUnsorted = from aun in dbContext.Adaptations
where aun.EventID == iep.EventID
select new Adaptation
{
StudentID = aun.StudentID,
EventID = aun.EventID,
Name = aun.Name,
Value = aun.Value
};
var adaptationsSorted = adaptationsUnsorted.ToList<Adaptation>().OrderBy(a => a.Name, new AdaptationComparer ());
foreach (Adaptation adaptation in adaptationsSorted)
{
// do real work
}
public class AdaptationComparer : IComparer<string>
{
public int Compare(string x, string y)
{
string x1 = Regex.Replace(x, #"ADAPT([0-9])$", #"ADAPT0$1");
string y1 = Regex.Replace(y, #"ADAPT([0-9])$", #"ADAPT0$1");
return Comparer<string>.Default.Compare(x1, y1);
}
}
I didn't test this code but it should do the job.

I wonder if you can add a calculated+persisted+indexed field to the database, that does this for you. It would be fairly trivial to write a UDF that gets the value as an integer (just using string values), but then you can sort on this column at the database. This would allow you to use Skip and Take effectively, rather than constantly fetching all the data to the .NET code (which simply doesn't scale).