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Query

الاستعلام (Query)

GLS-000092

Beginnerdatabase1 min read
firestore querydatabase queryfilterwhere clauseorderby
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Definition

A request to a database to retrieve specific documents that match certain conditions.

طلب إلى قاعدة البيانات لاسترداد مستندات محددة تستوفي شروطًا معينة.

Why It Matters

Efficient queries are critical for 404Fault's performance. Fetching only published projects ordered by date requires the right query with proper indexes.

الاستعلامات الكفؤة حاسمة لأداء 404Fault. جلب المشاريع المنشورة فقط مرتبةً حسب التاريخ يتطلب الاستعلام الصحيح مع الفهارس المناسبة.

Full Definition

A query filters and sorts documents in a Firestore collection to return only what you need. Common operations: where() to filter by field value, orderBy() to sort results, limit() to cap results, startAfter() for pagination. Firestore requires an index for most multi-field queries — if a query fails with an index error, Firestore provides a direct link to create the needed index.
الاستعلام يُرشِّح ويفرز المستندات في مجموعة Firestore لإرجاع ما تحتاجه فقط. العمليات الشائعة: where() للتصفية حسب قيمة الحقل وorderBy() لفرز النتائج وlimit() للحد من النتائج وstartAfter() للتصفح. يتطلب Firestore فهرسًا لمعظم الاستعلامات متعددة الحقول — إذا فشل استعلام بخطأ فهرس، يوفر Firestore رابطًا مباشرًا لإنشاء الفهرس المطلوب.

Example Usage

“db.collection('projects').where('status','==','published').orderBy('createdAt','desc').limit(12).get()”

“db.collection('projects').where('status','==','published').orderBy('createdAt','desc').limit(12).get()”

Knowledge Graph

AI Builder Tips

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Avoid these mistakes when using Query:

1

Missing index for multi-field queries

2

Fetching entire collections instead of using where() filters

3

Not using limit() (fetching thousands of documents when you need 10)

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Help me build a project using Query.

Explain:
1. What is Query and why it matters
2. The core architecture and required tools
3. Step-by-step implementation plan
4. Common mistakes to avoid: Missing index for multi-field queries, Fetching entire collections instead of using where() filters, Not using limit() (fetching thousands of documents when you need 10)
5. Best practices and production tips

Official Resources

Official Documentation
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