Sql-server – Different lock types on source table when I change method of inserting data

You've come across a fairly well-known problem. When SSIS is trying to import the data, it provides locale-aware conversions and the format YYYYMMDD doesn't convert nicely. You can use the "import as string and convert to actual datetime" approach you've outlined in your solution but that's slower and consumes more resources than using the native approach of telling SSIS to quit being so damn smart.

Right click on your flat file source and select the Show Advanced Editor. In the Input and Output Properties, expand Output Columns, find your column (BirthDate) and change the FastParse property from False to True.

With only that change, the package will execute successfully

Also, an excellent answer from SO on the same issue

You can use a script transformation to create the actual column mapping. For your flat file source, make every output line become a single large column.

In your script transformation, create column definitions for each column you need mapped / already know about.

This assumes your first line contains headers:

Then, in your script transformation , split each row by the delimiter you need. You can create a boolean value indicating if the first line has been read yet. If not, parse the line and store the column mapping positions in a Dictionary<string,int> such as ColumnMappings and do not write to OutputBuffer. If your row reader sees that the column mappings have been read, then you can set your output to the correct column with something like:

 OutputBuffer.MyMappedColumn = SplitRow[ColumnMappings["MyMappedColumn"]];

An example of an entire transformation with a column "Day" is below

using System;
using System.Data;
using System.Text;
using Microsoft.SqlServer.Dts.Pipeline.Wrapper;
using Microsoft.SqlServer.Dts.Runtime.Wrapper;

[Microsoft.SqlServer.Dts.Pipeline.SSISScriptComponentEntryPointAttribute]
public class ScriptMain : UserComponent {
    UTF8Encoding enc = new UTF8Encoding();
    char[] separator = { ',' };
    bool _isColumnMappingComplete = false;
    System.Collections.Generic.Dictionary<string, int> _columnMapping;
    bool isWritable = false;

    bool isColumnMappingComplete { //Set true after first row processed
        get{ return _isColumnMappingComplete; }
        set{ _isColumnMappingComplete = value;}   }

    System.Collections.Generic.Dictionary<string, int> columnMapping{ //Object to hold column mapping indexes
        get {
            if (_columnMapping == null) { _columnMapping = new System.Collections.Generic.Dictionary<string, int>(); }
            return _columnMapping; }
        set {
            _columnMapping = value;
            isColumnMappingComplete = true; } }

    public override void PreExecute() {
        base.PreExecute(); /* Add your code here for preprocessing or remove if not needed */ }

    public override void PostExecute()    {
        isWritable = true;
        base.PostExecute();
        /* Add your code here for postprocessing or remove if not needed
          You can set read/write variables here, for example: Variables.MyIntVar = 100 */  }

    public override void Input0_ProcessInputRow(Input0Buffer Row)    {
        bool isEmptyRow = false;
        //byte[] rawRowBytes = Row.Column0.GetBlobData(0,(int)Row.Column0.Length); //uncomment if using Text input datatype
        //string rawRow = enc.GetString(rawRowBytes); //uncomment if using Text input datatype
        string rawRow = Row.Column0; //comment out if using Text input datatype
        if (rawRow.Replace("\"", "").Replace(",", "").Replace(" ", "").Length == 0)
        { isEmptyRow = true; }
        if (!isEmptyRow) {
            string[] rowData = rawRow.Split(separator);

            if (!isColumnMappingComplete) {
                System.Collections.Generic.Dictionary<string, int> firstColMap = new System.Collections.Generic.Dictionary<string, int>();
                for (int i = 0; i < rowData.Length; i++)
                { firstColMap.Add(rowData[i], i); }
                columnMapping = firstColMap;    }
            else {
                Output0Buffer.AddRow();
                bool _rowError = false;
                //Day
                if (columnMapping.ContainsKey("Day"))
                { Output0Buffer.Day = rowData[columnMapping["Day"]]; }
                else
                { //Output0Buffer.Day = "-";
                    _rowError = true; }   }      }    }

    public override void CreateNewOutputRows()
    {   /* Add rows by calling the AddRow method on the member variable named "<Output Name>Buffer".
         * For example, call MyOutputBuffer.AddRow() if your output was named "MyOutput". */ }     }