Dropping data in foreach loop - php

Question

Using this array:
$arr=array(
array('project','ProjectId','62c1553d'),
array('project','ProjectName','TEST JSON'),
array('Vendors','PrimeSpec','Fabspec'),
array('Vendors','VendorId','dd759c7f'),
array('Vendors','PrimeSpec','Vendor2'),
array('Vendors','VendorId','Vendor2ID'),
);
The desired result is:
INSERT INTO project (ProjectId,ProjectName) VALUES (62c1553d,'TEST JSON');
INSERT INTO Vendors (PrimeSpec,VendorId) VALUES ('Fabspec',dd759c7f);
INSERT INTO Vendors (PrimeSpec,VendorId) VALUES ('Vendor2',Vendor2ID);
But I'm losing PrimeSpec, Fabspec in the foreach loop - the output I'm getting is:
INSERT INTO project (ProjectId,ProjectName) VALUES (62c1553d,TEST JSON);
INSERT INTO Vendors (VendorId) VALUES (dd759c7f);
Here is my code:
function array2sql($arr){
$sql = '';
$fields = '';
$values = '';
$extable = $arr[0][0];
foreach( $arr as $line ) {
if ($extable == $line[0]) {
$fields .= $line[1].',';
$values .= $line[2].',';
} else {
$sql .= 'INSERT INTO ' . $extable . ' (' . rtrim($fields, ',') . ') VALUES (' . rtrim($values, ',') . ');';
$fields = '';
$values = '';
$extable = $line[0];
}
}
$sql .= 'INSERT INTO ' . $extable . ' (' . rtrim($fields, ',') . ') VALUES (' . rtrim($values, ',') . ');';
echo $sql;
return $arr;
}
array2sql($arr);
I don't understand why it's dropping the first set of data. Thanks for looking at this.

Answer 1

Consider the following simplified version of your array2sql function(using array_walk and array_column functions):
function array2sql($arr) {
$query_data = [];
$sql = "";
array_walk($arr, function($v) use(&$query_data) {
$query_data[$v[0]][$v[1]][] = $v[2];
});
foreach ($query_data as $table => $data) {
$keys = array_keys($data);
$key_string = implode(",", $keys);
$count = count($data[$keys[0]]); // number of values for a certain column
while ($count--) {
$value_string = "'". implode("','", array_column($data, $count)). "'";
$sql .= "INSERT INTO $table($key_string) VALUES($value_string);". PHP_EOL;
}
}
return $sql;
}
print_r(array2sql($arr));
The output:
INSERT INTO project(ProjectId,ProjectName) VALUES('62c1553d','TEST JSON');
INSERT INTO Vendors(PrimeSpec,VendorId) VALUES('Vendor2','Vendor2ID');
INSERT INTO Vendors(PrimeSpec,VendorId) VALUES('Fabspec','dd759c7f');

Answer 2

Seems to be resolved by changing the else statement to
$fields = $line[1].',';
$values = $line[2].',';

Answer 3

Try This
function array2sql($arr){
$sql = '';
$newArr = array();
foreach( $arr as $line ) {
$newArr[$line[0]][$line[1]] = $line[2];
}
foreach($newArr as $tblNam=>$value) {
$sql .= "INSERT INTO ".$tblNam." (`" . implode('`,`', array_keys($value)) . "`) VALUES ('" . implode("','", array_values($value)) . "') ";
}
echo $sql;
}

Answer 4

Because your tables are only receiving two columns of data each, array_chunk() can help to merge and prepare and compose the queries.
$arr=array(
array('project','ProjectId','62c1553d'),
array('project','ProjectName','TEST JSON'),
array('Vendors','PrimeSpec','Fabspec'),
array('Vendors','VendorId','dd759c7f'),
array('Vendors','PrimeSpec','Vendor2'),
array('Vendors','VendorId','Vendor2ID'),
);
// merge and prepare
foreach(array_chunk($arr,2) as $pair){
if(!isset($queries[$pair[0][0]]['columns'])){
$merge[$pair[0][0]]['columns']='`'.implode('`,`',array_column($pair,1)).'`';
}
$merge[$pair[0][0]]['values'][]="'".implode("','",array_column($pair,2))."'";
}
// compose queries
foreach($merge as $table=>$a){
$queries[$table]="INSERT INTO $table ({$a['columns']}) VALUES (".implode('),(',$a['values']).")";
}
print_r($queries);
/*
Array(
[project] => INSERT INTO project (`ProjectId`,`ProjectName`) VALUES ('62c1553d','TEST JSON')
[Vendors] => INSERT INTO Vendors (`PrimeSpec`,`VendorId`) VALUES ('Fabspec','dd759c7f'),('Vendor2','Vendor2ID')
)
*/
$mysqli->multi_query(implode(';',$queries));
while ($mysqli->next_result()) {;} // flush multi_queries
This method performs no escaping or security measures. If you want to use prepared statements and placeholders, a few modifications will be necessary.
For more details on how to write a full mysqli_multi_query() INSERT block, see this link: Strict Standards: mysqli_next_result() error with mysqli_multi_query