How to update,insert in table from source to destination

You can use this

MERGE Data2 AS Target
USING Data AS Source
ON Source.Abc= Target.A_Abc and Source.cde= Target.A_cde
    
-- For Inserts
WHEN NOT MATCHED BY Target THEN
    INSERT (A_Abc,A_cde, A_efg) 
    VALUES (Source.Abc,Source.cde, Source.efg)
    
-- For Updates
WHEN MATCHED THEN UPDATE SET
    Target.A_Abc	= Source.Abc,
    Target.A_cde		= Source.cde
     Target.A_efg		= Source.efg
    
    
-- For Deletes
WHEN NOT MATCHED BY Source THEN
    DELETE;

 Data.cs(source class ) no primary and foreign key relationship and column values are same type but names are different between source and destination table

 public class Data
    {
        public string Abc { get; set; }
        public string cde { get; set; }
        public string efg{ get; set; }
      }

Data2.cs(destination class)no primary and foreign key relationship

public class data2

{

       public string A_Abc { get; set; }
        public string A_cde { get; set; }
        public string A_efg{ get; set; }

}

source table

column name :abc,bcd,egf

destination table:

column name:A_abc,A_bcd,A_egf

error:-

'Data table requires a primary key to be defined. If you intended to use a keyless entity type, call 'HasNoKey' in 'OnModelCreating'

after adding Hasnokey in Data2DBcontext.cs(destination.cs)

 protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
          base.OnModelCreating(modelBuilder);
            modelBuilder.Entity().HasNoKey();
        }

getting invalid column names error

 source class

 public class Data
    {
        public string Abc { get; set; }
        public string cde { get; set; }
        public string efg{ get; set; }
      }

destination class

public class data2

{

       public string A_Abc { get; set; }
        public string A_cde { get; set; }
        public string A_efg{ get; set; }

}

source table: no primary key

column name :abc,bcd,egf

destination table:

column name:A_abc,A_bcd,A_egf

Stored procedure for truncate and insert data from source to destination 

ok.Thank you

To perform an insert/update/delete operation on the destination table based on the data from the source table, you can use the following steps:

1. Use a query to identify the matching records between the source and destination tables. This can be done by comparing the values in one or more columns that are common to both tables. For example, if the tables have a common "Name" column, you can use that column to match records between the tables.

2. For the records that match between the source and destination tables, perform the appropriate action based on whether the record already exists in the destination table or not.

• If the record exists in the destination table, update its values with the corresponding values from the source table.
• If the record doesn't exist in the destination table, insert it with the values from the source table.

1. For the records in the destination table that don't have a matching record in the source table, delete them from the destination table.

It's important to note that without a primary key or a unique constraint on a column(s), there may be duplicates or inconsistencies in the data after the merge. Therefore, it's recommended to create a primary key or a unique constraint on the destination table before performing the merge.

Thanks

Pls Take Similar Values which u have passed in the first table u should  need to match the values with 2nd table