Bulk Update in EF Core- Old vs New

📌 Problem Before EF7 (EF6 and below):

When you wanted to update multiple records:

• You had to load the data into memory.

• Loop through and modify each entity.

• Call SaveChangesAsync() which sends multiple UPDATE statements to the database.

🧱 Traditional Way (Before EF7)

// EF6 or EF Core < 7
var productIdsToUpdate = new List<int> { 1, 2, 3 };
 
var products = await dbContext.Products
    .Where(p => productIdsToUpdate.Contains(p.Id))
    .ToListAsync();
 
foreach (var product in products)
{
    product.IsActive = false; // Mark as inactive
}
 
await dbContext.SaveChangesAsync(); // Multiple UPDATEs under the hood

❌ Drawback: All records are loaded into memory and updated one by one – this is slow and memory-intensive for large datasets.

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✅ New & Efficient Way in EF Core 7+

ExecuteUpdateAsync to the rescue!

// EF Core 7+
var productIdsToUpdate = new List<int> { 1, 2, 3 };
 
await dbContext.Products
    .Where(p => productIdsToUpdate.Contains(p.Id))
    .ExecuteUpdateAsync(setters => setters
        .SetProperty(p => p.IsActive, false)
    );

✅ Benefit: Generates a single SQL UPDATE statement like:

UPDATE Products
SET IsActive = 0
WHERE Id IN (1, 2, 3)

🔥 Why it matters:

• No need to load data into memory.

• No need for EF change tracking.

• Fast, lightweight, and scales well.

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🔁 Use Cases

• Bulk status updates (e.g., mark records inactive/archived)

• Flag updates (e.g., IsDeleted, IsSynced)

• Audit field updates (e.g., UpdatedAt, UpdatedBy)

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⚠️ Requirements

• ExecuteUpdateAsync is available only in EF Core 7+.

• Works only with LINQ queries directly targeting a single entity/table (no includes or complex projections).