stored procedure with dynamic

HI All,

could you please help me to create the dynamic stored procedure i already written it but seems like need to improve,plz see the screen in attachment.

I have to create dynamic stored procedure with some criteria
Validation
1.if none of the fields provided it will not search anything
2.(First Name should not be the only search criteriaits) it will not search if only provided firstname,
if user is providing first name then he should also provide the last name.then it will search
3.last name should be at least 3 character,other wise raise issue to user
4.its should be search with other parameter like medicare id ,medicaid id and date of birth
5.here also some issue with date which i used like ,i know its wrong.

Please help me to make a perfect stored procedure


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CREATE PROCEDURE SGetPatientInfo
                              @in_vcLastName                  varchar(30),
                        @in_vcFirstName                  varchar(17),
                        @in_dtDOB                        DateTime,
                        @in_nMedicaidID                  numeric,                        
                        @in_nMPID                          numeric,      
                        @in_nMedicare                     numeric

      
AS
BEGIN

DECLARE @sSqlStart Varchar(1000),
            @sSqlEnd Varchar(100)       

SET NOCOUNT ON

      Set @sSqlStart=''      
      Set @sSqlEnd=''

      IF @in_vcLastName = ''
            Begin
                  Set @in_vcLastName = '%'
            End

      IF in_vcFirstName = ''
            Begin
                  Set in_vcFirstName = '%'
            End

      IF @in_dtDOB = ''
            Begin
                  Set @in_dtDOB = '%'
            End

      IF @in_nMedicaidID = ''
            Begin
                  Set @in_nMedicaidID = '%'
            End
      
      IF @in_nMPID = ''
            Begin
                  Set @in_nMPID = '%'
            End

      IF @in_nMedicare = ''
            Begin
                  Set @in_nMedicare = '%'
            End

      Else
            Begin
                  Set in_vcFirstName = in_vcFirstName + '%'
            End            

            Set @sSqlStart=      'SELECT
                        Last_Name      AS      LastName,
                        First_Name        AS      FirstName,
                            Patient_ID      AS      PatientID,
                            Birth_Date      AS      BirthDate,
                        SSN              AS      SSN,
                        Gender              AS      Gender,
                        Age              AS      Age,

                            
                  FROM
                        Patient PT

                  INNER JOIN PatientSecIds PS

                  ON
                  PT.Patient_Key = PS.Patient_Key

                  WHERE
                        PT.Last_Name like ' + '''' + @in_vcLastName  + '''' + '
                        AND PT.First_Name like ' + '''' + @in_vcFirstName  + '''' + '
                        AND PT.Birth_Date like ' + '''' + @in_dtDOB + '''' + '
                        AND PS.Medicadeid like ' + '''' + @in_nMedicaidID  + '''' + '
                        AND PS.MPID like ' + '''' + @in_nMPID + '''' + '
                        AND PS.MediCare like ' + '''' + @in_nMedicare + '''' + '

                              
        
                  Begin
                        Set @sSqlEnd = 'Order By First_Name Asc'
                  End

      EXEC (@sSqlStart + @sSqlEnd)

SET NOCOUNT OFF

END
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