php - For-loop and variables in PHP MySQL Query

Question

I have to select a lot of tables and Fields using PHP and MySQL. But the structure and naming of these are every time the same.

I have the tables field_revision_blabla and the fields blablabla_value from table-alias blablabla_table.

for ($i=0; $i < sizeof($typeFields); $i++) {
    $query->join(
        "field_revision_".$typeFields[$i], 
        $typeFields[$i]."_table", 
        'n.nid = $typeFields[$i]."_table.entity_id"');
    $query->addField($typeFields[$i]."_table", $typeFields[$i]."_value");
}

But that gives me the error:

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '[$i])."_table.entity_id" INNER JOIN field_revision_field_text field_text_table O' at line 2

I think the error is in

'n.nid = $typeFields[$i]."_table.entity_id"'

Answer 1

SO 的颜色编码应该已经为您标记了这一点……以及抱怨查询中的变量的 SQL 语句。您$typeFields[$i]没有在字符串中计算出来。

"n.nid = " . $typeFields[$i] . "_table.entity_id"

Answer 2

使用双引号而不是单引号，我怀疑您在 DB 中的记录包含n.nid = $typeFields[$i]."_table.entity_id"：

for ($i=0; $i < sizeof($typeFields); $i++) {
    $query->join(
        "field_revision_".$typeFields[$i], 
        $typeFields[$i]."_table", 
        "n.nid = ".$typeFields[$i]."_table.entity_id");
    $query->addField($typeFields[$i]."_table", $typeFields[$i]."_value");
}