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SqlServerGrammar with OFFSET..FETCH support
<?php
namespace Illuminate\Database\Query\Grammars;
use Illuminate\Support\Arr;
use Illuminate\Database\Query\Builder;
class SqlServerGrammar extends Grammar
{
/**
* All of the available clause operators.
*
* @var array
*/
protected $operators = [
'=', '<', '>', '<=', '>=', '!<', '!>', '<>', '!=',
'like', 'not like', 'ilike',
'&', '&=', '|', '|=', '^', '^=',
];
/**
* Compile a select query into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @return string
*/
public function compileSelect(Builder $query)
{
// If order & offset is provided, we can use OFFSET...FETCH
if (!is_null($query->orders) && !is_null($query->offset)) {
return parent::compileSelect($query);
}
if (! $query->offset) {
return parent::compileSelect($query);
}
// If an offset is present on the query, we will need to wrap the query in
// a big "ANSI" offset syntax block. This is very nasty compared to the
// other database systems but is necessary for implementing features.
if (is_null($query->columns)) {
$query->columns = ['*'];
}
return $this->compileAnsiOffset(
$query, $this->compileComponents($query)
);
}
/**
* Compile the "select *" portion of the query.
*
* @param \Illuminate\Database\Query\Builder $query
* @param array $columns
* @return string|null
*/
protected function compileColumns(Builder $query, $columns)
{
if (! is_null($query->aggregate)) {
return;
}
$select = $query->distinct ? 'select distinct ' : 'select ';
// If there is a limit on the query, but not an offset, we will add the top
// clause to the query, which serves as a "limit" type clause within the
// SQL Server system similar to the limit keywords available in MySQL.
if ($query->limit > 0 && is_null($query->offset)) {
$select .= 'top '.$query->limit.' ';
}
return $select.$this->columnize($columns);
}
/**
* Compile the "from" portion of the query.
*
* @param \Illuminate\Database\Query\Builder $query
* @param string $table
* @return string
*/
protected function compileFrom(Builder $query, $table)
{
$from = parent::compileFrom($query, $table);
if (is_string($query->lock)) {
return $from.' '.$query->lock;
}
if (! is_null($query->lock)) {
return $from.' with(rowlock,'.($query->lock ? 'updlock,' : '').'holdlock)';
}
return $from;
}
/**
* Compile a "where date" clause.
*
* @param \Illuminate\Database\Query\Builder $query
* @param array $where
* @return string
*/
protected function whereDate(Builder $query, $where)
{
$value = $this->parameter($where['value']);
return 'cast('.$this->wrap($where['column']).' as date) '.$where['operator'].' '.$value;
}
/**
* Create a full ANSI offset clause for the query.
*
* @param \Illuminate\Database\Query\Builder $query
* @param array $components
* @return string
*/
protected function compileAnsiOffset(Builder $query, $components)
{
// An ORDER BY clause is required to make this offset query work, so if one does
// not exist we'll just create a dummy clause to trick the database and so it
// does not complain about the queries for not having an "order by" clause.
if (empty($components['orders'])) {
$components['orders'] = 'order by (select 0)';
}
// We need to add the row number to the query so we can compare it to the offset
// and limit values given for the statements. So we will add an expression to
// the "select" that will give back the row numbers on each of the records.
$components['columns'] .= $this->compileOver($components['orders']);
unset($components['orders']);
// Next we need to calculate the constraints that should be placed on the query
// to get the right offset and limit from our query but if there is no limit
// set we will just handle the offset only since that is all that matters.
$sql = $this->concatenate($components);
return $this->compileTableExpression($sql, $query);
}
/**
* Compile the over statement for a table expression.
*
* @param string $orderings
* @return string
*/
protected function compileOver($orderings)
{
return ", row_number() over ({$orderings}) as row_num";
}
/**
* Compile a common table expression for a query.
*
* @param string $sql
* @param \Illuminate\Database\Query\Builder $query
* @return string
*/
protected function compileTableExpression($sql, $query)
{
$constraint = $this->compileRowConstraint($query);
return "select * from ({$sql}) as temp_table where row_num {$constraint}";
}
/**
* Compile the limit / offset row constraint for a query.
*
* @param \Illuminate\Database\Query\Builder $query
* @return string
*/
protected function compileRowConstraint($query)
{
$start = $query->offset + 1;
if ($query->limit > 0) {
$finish = $query->offset + $query->limit;
return "between {$start} and {$finish}";
}
return ">= {$start}";
}
/**
* Compile the random statement into SQL.
*
* @param string $seed
* @return string
*/
public function compileRandom($seed)
{
return 'NEWID()';
}
/**
* Compile the "limit" portions of the query.
*
* @param \Illuminate\Database\Query\Builder $query
* @param int $limit
* @return string
*/
protected function compileLimit(Builder $query, $limit)
{
// If offset is not provided, TOP syntax will handle limits
if (is_null($query->offset)) {
return '';
}
// If offset & orders exist, then use OFFSET...FETCH
if (!is_null($query->offset) && !is_null($query->orders)) {
return "OFFSET {$query->offset} ROWS FETCH NEXT {$limit} ROWS ONLY";
}
return '';
}
/**
* Compile the "offset" portions of the query.
*
* @param \Illuminate\Database\Query\Builder $query
* @param int $offset
* @return string
*/
protected function compileOffset(Builder $query, $offset)
{
// If limit exists, compileLimit to handle both offset & limit.
if (!is_null($query->limit)) {
return '';
}
// ORDER BY has to exist for OFFSET to work
if (!is_null($query->orders)) {
return "OFFSET {$offset} ROWS";
}
return '';
}
/**
* Compile the lock into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @param bool|string $value
* @return string
*/
protected function compileLock(Builder $query, $value)
{
return '';
}
/**
* Compile an exists statement into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @return string
*/
public function compileExists(Builder $query)
{
$existsQuery = clone $query;
$existsQuery->columns = [];
return $this->compileSelect($existsQuery->selectRaw('1 [exists]')->limit(1));
}
/**
* Compile a delete statement into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @return string
*/
public function compileDelete(Builder $query)
{
$table = $this->wrapTable($query->from);
$where = is_array($query->wheres) ? $this->compileWheres($query) : '';
return isset($query->joins)
? $this->compileDeleteWithJoins($query, $table, $where)
: trim("delete from {$table} {$where}");
}
/**
* Compile a delete statement with joins into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @param string $table
* @param string $where
* @return string
*/
protected function compileDeleteWithJoins(Builder $query, $table, $where)
{
$joins = ' '.$this->compileJoins($query, $query->joins);
$alias = strpos(strtolower($table), ' as ') !== false
? explode(' as ', $table)[1] : $table;
return trim("delete {$alias} from {$table}{$joins} {$where}");
}
/**
* Compile a truncate table statement into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @return array
*/
public function compileTruncate(Builder $query)
{
return ['truncate table '.$this->wrapTable($query->from) => []];
}
/**
* Compile an update statement into SQL.
*
* @param \Illuminate\Database\Query\Builder $query
* @param array $values
* @return string
*/
public function compileUpdate(Builder $query, $values)
{
list($table, $alias) = $this->parseUpdateTable($query->from);
// Each one of the columns in the update statements needs to be wrapped in the
// keyword identifiers, also a place-holder needs to be created for each of
// the values in the list of bindings so we can make the sets statements.
$columns = collect($values)->map(function ($value, $key) {
return $this->wrap($key).' = '.$this->parameter($value);
})->implode(', ');
// If the query has any "join" clauses, we will setup the joins on the builder
// and compile them so we can attach them to this update, as update queries
// can get join statements to attach to other tables when they're needed.
$joins = '';
if (isset($query->joins)) {
$joins = ' '.$this->compileJoins($query, $query->joins);
}
// Of course, update queries may also be constrained by where clauses so we'll
// need to compile the where clauses and attach it to the query so only the
// intended records are updated by the SQL statements we generate to run.
$where = $this->compileWheres($query);
if (! empty($joins)) {
return trim("update {$alias} set {$columns} from {$table}{$joins} {$where}");
}
return trim("update {$table}{$joins} set $columns $where");
}
/**
* Get the table and alias for the given table.
*
* @param string $table
* @return array
*/
protected function parseUpdateTable($table)
{
$table = $alias = $this->wrapTable($table);
if (strpos(strtolower($table), '] as [') !== false) {
$alias = '['.explode('] as [', $table)[1];
}
return [$table, $alias];
}
/**
* Prepare the bindings for an update statement.
*
* @param array $bindings
* @param array $values
* @return array
*/
public function prepareBindingsForUpdate(array $bindings, array $values)
{
// Update statements with joins in SQL Servers utilize an unique syntax. We need to
// take all of the bindings and put them on the end of this array since they are
// added to the end of the "where" clause statements as typical where clauses.
$bindingsWithoutJoin = Arr::except($bindings, 'join');
return array_values(
array_merge($values, $bindings['join'], Arr::flatten($bindingsWithoutJoin))
);
}
/**
* Determine if the grammar supports savepoints.
*
* @return bool
*/
public function supportsSavepoints()
{
return true;
}
/**
* Compile the SQL statement to define a savepoint.
*
* @param string $name
* @return string
*/
public function compileSavepoint($name)
{
return 'SAVE TRANSACTION '.$name;
}
/**
* Compile the SQL statement to execute a savepoint rollback.
*
* @param string $name
* @return string
*/
public function compileSavepointRollBack($name)
{
return 'ROLLBACK TRANSACTION '.$name;
}
/**
* Get the format for database stored dates.
*
* @return string
*/
public function getDateFormat()
{
return 'Y-m-d H:i:s.v';
}
/**
* Wrap a single string in keyword identifiers.
*
* @param string $value
* @return string
*/
protected function wrapValue($value)
{
return $value === '*' ? $value : '['.str_replace(']', ']]', $value).']';
}
/**
* Wrap a table in keyword identifiers.
*
* @param \Illuminate\Database\Query\Expression|string $table
* @return string
*/
public function wrapTable($table)
{
return $this->wrapTableValuedFunction(parent::wrapTable($table));
}
/**
* Wrap a table in keyword identifiers.
*
* @param string $table
* @return string
*/
protected function wrapTableValuedFunction($table)
{
if (preg_match('/^(.+?)(\(.*?\))]$/', $table, $matches) === 1) {
$table = $matches[1].']'.$matches[2];
}
return $table;
}
}
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