programmatically generate script for a table

this is a sql script to genrate table script

declare @vsSQL varchar(8000)
declare @vsTableName varchar(50)
select @vsTableName = '_PRODUCT'--- Your Table Name here

select @vsSQL = 'CREATE TABLE ' + @vsTableName + char(10) + '(' + char(10)

select @vsSQL = @vsSQL + ' ' + sc.Name + ' ' +
st.Name +
case when st.Name in ('varchar','varchar','char','nchar') then '(' + cast(sc.Length as varchar) + ') ' else ' ' end +
case when sc.IsNullable = 1 then 'NULL' else 'NOT NULL' end + ',' + char(10)
from sysobjects so
join syscolumns sc on sc.id = so.id
join systypes st on st.xusertype = sc.xusertype
where so.name = @vsTableName
order by
sc.ColID

select substring(@vsSQL,1,len(@vsSQL) - 2) + char(10) + ')'

Edit: c# code

public string GetScript(string strConnectionString
                      , string strObject
                      , int ObjType)
{
    string strScript = null;
    int intCounter = 0;
    if (ObjType != 0)
    {
        ObjSqlConnection = new SqlConnection(strConnectionString.Trim());

        try
        {
            ObjDataSet = new DataSet();
            ObjSqlCommand = new SqlCommand("exec sp_helptext 
                [" + strObject + "]", ObjSqlConnection);
            ObjSqlDataAdapter = new SqlDataAdapter();
            ObjSqlDataAdapter.SelectCommand = ObjSqlCommand;
            ObjSqlDataAdapter.Fill(ObjDataSet);

            foreach (DataRow ObjDataRow in ObjDataSet.Tables[0].Rows)
            {
                strScript += Convert.ToString(ObjDataSet.Tables[0].Rows[intCounter][0]);
                intCounter++;
            }
        }
        catch (Exception ex)
        {
           strScript = ex.Message.ToString();
        }
        finally
        {
            ObjSqlDataAdapter = null;
            ObjSqlCommand = null;
            ObjSqlConnection = null;
        }
    }

    return strScript;
}

To create Insert script use this store procedure

IF EXISTS (SELECT * FROM dbo.sysobjects 
WHERE id = OBJECT_ID(N'[dbo].[InsertGenerator]') AND OBJECTPROPERTY(id,N'IsProcedure') = 1)
DROP PROCEDURE [dbo].[InsertGenerator]
GO

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER OFF
GO

CREATE PROC [dbo].[InsertGenerator]
(
@tableName varchar(100),
@KeyColumn1 varchar(100)='',
@KeyColumn2 varchar(100)=''
)
AS

-- Generating INSERT statements in SQL Server
-- to validate if record exists - supports 2 field Unique index

--Declare a cursor to retrieve column specific information for the specified table
DECLARE cursCol CURSOR FAST_FORWARD FOR 
SELECT column_name,data_type FROM information_schema.columns WHERE table_name = @tableName

OPEN cursCol

DECLARE @string nvarchar(max) --for storing the first half of INSERT statement
DECLARE @stringData nvarchar(max) --for storing the data (VALUES) related statement
DECLARE @dataType nvarchar(1000) --data types returned for respective columns
DECLARE @FieldVal nvarchar(1000) -- save value for the current field
DECLARE @KeyVal nvarchar(1000) -- save value for the current field
DECLARE @KeyTest0 nvarchar(1000) -- used to test if key exists
DECLARE @KeyTest1 nvarchar(1000) -- used to test if key exists
DECLARE @KeyTest2 nvarchar(1000) -- used to test if key exists

SET @KeyTest0=''

IF @KeyColumn1<>''
SET @KeyTest0='IF not exists (Select * from '+@tableName

SET @KeyTest1=''
SET @KeyTest2=''

SET @string='INSERT '+@tableName+'('
SET @stringData=''
SET @FieldVal=''
SET @KeyVal=''

DECLARE @colName nvarchar(50)

FETCH NEXT FROM cursCol INTO @colName,@dataType

IF @@fetch_status<>0
begin
    print 'Table '+@tableName+' not found, processing skipped.'
    close curscol
    deallocate curscol
    return
END

WHILE @@FETCH_STATUS=0
BEGIN

IF @dataType in ('varchar','char','nchar','nvarchar')
BEGIN
    SET @FieldVal=''''+'''+isnull('''''+'''''+'+@colName+'+'''''+''''',''NULL'')+'',''+'
    SET @KeyVal='''+isnull('''''+'''''+'+@colName+'+'''''+''''',''NULL'')+'',''+'
    SET @stringData=@stringData+@FieldVal
END

ELSE

if @dataType in ('text','ntext','xml') --if the datatype is text or something else 
BEGIN
    SET @FieldVal='''''''''+isnull(cast('+@colName+' as varchar(max)),'''')+'''''',''+'
    SET @stringData=@stringData+@FieldVal
END
ELSE
IF @dataType = 'money' --because money doesn't get converted from varchar implicitly
BEGIN
    SET @FieldVal='''convert(money,''''''+isnull(cast('+@colName+' as varchar(200)),''0.0000'')+''''''),''+'
    SET @stringData=@stringData+@FieldVal
END
ELSE 
IF @dataType='datetime'
BEGIN
    SET @FieldVal='''convert(datetime,'+'''+isnull('''''+'''''+convert(varchar(200),'+@colName+',121)+'''''+''''',''NULL'')+'',121),''+'
    SET @stringData=@stringData+@FieldVal
END
ELSE 
IF @dataType='image' 
BEGIN
    SET @FieldVal='''''''''+isnull(cast(convert(varbinary,'+@colName+') as varchar(6)),''0'')+'''''',''+'
    SET @stringData=@stringData+@FieldVal
END
ELSE --presuming the data type is int,bit,numeric,decimal 
BEGIN
    SET @FieldVal=''''+'''+isnull('''''+'''''+convert(varchar(200),'+@colName+')+'''''+''''',''NULL'')+'',''+'
    SET @KeyVal='''+isnull('''''+'''''+convert(varchar(200),'+@colName+')+'''''+''''',''NULL'')+'',''+'
    SET @stringData=@stringData+@FieldVal
END

--Build key test
IF @KeyColumn1=@colName
begin
    SET @KeyTest1 = ' WHERE [' + @KeyColumn1 + ']='
    SET @KeyTest1 = @KeyTest1+@KeyVal+']'
end
IF @KeyColumn2=@colName
begin
    SET @KeyTest2 = ' AND [' + @KeyColumn2 + ']='
    SET @KeyTest2 = @KeyTest2+@KeyVal+']'
end

SET @string=@string+'['+@colName+'],'

FETCH NEXT FROM cursCol INTO @colName,@dataType
END

DECLARE @Query nvarchar(max)

-- Build the test string to check if record exists
if @KeyTest0<>''
begin
    if @Keycolumn1<>''
        SET @KeyTest0 = @KeyTest0 + substring(@KeyTest1,0,len(@KeyTest1)-4)
    if @Keycolumn2<>''
    begin
        SET @KeyTest0 = @KeyTest0 + ''''
        SET @KeyTest0 = @KeyTest0 + substring(@KeyTest2,0,len(@KeyTest2)-4)
    end
    SET @KeyTest0 = @KeyTest0 + ''')'

    SET @query ='SELECT '''+substring(@KeyTest0,0,len(@KeyTest0)) + ') ' 
end
else
    SET @query ='SELECT '''+substring(@KeyTest0,0,len(@KeyTest0))

SET @query = @query + substring(@string,0,len(@string)) + ') ' 
SET @query = @query + 'VALUES(''+ ' + substring(@stringData,0,len(@stringData)-2)+'''+'')'' FROM '+@tableName

exec sp_executesql @query

CLOSE cursCol
DEALLOCATE cursCol

GO

and use of InsertGenerator like below

DECLARE @return_value int

EXEC    @return_value = [dbo].[InsertGenerator]
        @tableName = N'_PRODUCT'

SELECT  'Return Value' = @return_value

Expanding upon Imran Ali Khan's answer to

• properly handle text datatypes (his had typo varchar instead of nvarchar)
• handle max text length type
• handle numeric/decimal datatype's precision and scale
• handle computed columns
• add the IDENTITY(1,1) and named primary keys at the end as SSMS does
• use the correct datatype for table name nvarchar(128)
• use nvarchar(max) instead of varchar(8000) for outputting large tables

The output formatting is similar to SSMS scripting output.

declare @crlf nchar(2);
set @crlf = char(13) + char(10);
declare @createScript nvarchar(max)
declare @tableName nvarchar(128)
select @tableName = N'singer_and_album'--- Your Table Name here

select @createScript = N'CREATE TABLE [dbo].[' + @tableName + N'](' + @crlf

select @createScript = @createScript + char(9) + N'[' + sc.[name] + N'] ' +
case when sc.is_computed = 1 then
    N' AS ' + cc.[definition]
else
    st.[name] +
    case
        when st.[name] in ('varchar','nvarchar','char','nchar') then '(' + case when sc.max_length = -1 then N'max' else cast(sc.max_length as varchar) end + N')'
        when st.[name] in ('decimal','numeric') then N'(' + cast(sc.precision as varchar) + N',' + cast(sc.scale as varchar) + N')'
        else N''
    end +
    case when sc.is_identity = 1 then N' IDENTITY(1,1) ' else N' ' end +
    case when sc.is_nullable = 1 then N'NULL' else N'NOT NULL' end
end +
N',' + @crlf
from sys.columns sc
join sys.types st on st.user_type_id = sc.user_type_id
left outer join sys.computed_columns cc on cc.[object_id] = sc.[object_id] and cc.column_id = sc.[column_id]
where sc.[object_id] = object_id(@tableName)
order by
sc.column_id;
set @createScript = left(@createScript,len(@createScript) - 3); -- trim last comma

if exists(select * from sys.indexes where [object_id] = object_id(@tableName) and is_primary_key = 1)
begin
    set @createScript = @createScript + N',' + @crlf + N' CONSTRAINT [' +
    (select top 1 [name] from sys.indexes where object_id = object_id(@tableName) and is_primary_key = 1) + N'] PRIMARY KEY CLUSTERED ' + @crlf + N'(' + @crlf;

    select @createScript = @createScript +
    char(9) + N'[' + sc.[name] + N'] ' + case when ic.is_descending_key = 1 then N'DESC' else N'ASC' end + N',' + @crlf
    from sys.index_columns ic
    join sys.columns sc on ic.[object_id] = sc.[object_id] and ic.column_id = sc.column_id
    join sys.indexes si on ic.[object_id] = si.[object_id] and ic.index_id = si.index_id
    where ic.object_id = object_id(@tableName) and si.is_primary_key = 1
    order by ic.index_column_id;

    set @createScript = left(@createScript,len(@createScript) - 3) + @crlf + N')' -- trim last comma
end

select @createScript + @crlf + N')';

Known issues:

• Assumes your table is in schema dbo
• Assumes your identity column is IDENTITY(1,1)
• Assumes you only have one primary key index (however it does support multiple columns)
• Doesn't script index flags such as padding, ignore_dup_key, etc
• Doesn't support datetime2 length other then 7 (default)