azure-data-tables-java

# Azure Tables SDK for Java

Build table storage applications using the Azure Tables SDK for Java. Works with both Azure Table Storage and Cosmos DB Table API.

## Installation

```xml
<dependency>
  <groupId>com.azure</groupId>
  <artifactId>azure-data-tables</artifactId>
  <version>12.6.0-beta.1</version>
</dependency>
```

## Client Creation

### With Connection String

```java
import com.azure.data.tables.TableServiceClient;
import com.azure.data.tables.TableServiceClientBuilder;
import com.azure.data.tables.TableClient;

TableServiceClient serviceClient = new TableServiceClientBuilder()
    .connectionString("<your-connection-string>")
    .buildClient();
```

### With Shared Key

```java
import com.azure.core.credential.AzureNamedKeyCredential;

AzureNamedKeyCredential credential = new AzureNamedKeyCredential(
    "<account-name>",
    "<account-key>");

TableServiceClient serviceClient = new TableServiceClientBuilder()
    .endpoint("<your-table-account-url>")
    .credential(credential)
    .buildClient();
```

### With SAS Token

```java
TableServiceClient serviceClient = new TableServiceClientBuilder()
    .endpoint("<your-table-account-url>")
    .sasToken("<sas-token>")
    .buildClient();
```

### With DefaultAzureCredential (Storage only)

```java
import com.azure.identity.DefaultAzureCredentialBuilder;

TableServiceClient serviceClient = new TableServiceClientBuilder()
    .endpoint("<your-table-account-url>")
    .credential(new DefaultAzureCredentialBuilder().build())
    .buildClient();
```

## Key Concepts

- **TableServiceClient**: Manage tables (create, list, delete)
- **TableClient**: Manage entities within a table (CRUD)
- **Partition Key**: Groups entities for efficient queries
- **Row Key**: Unique identifier within a partition
- **Entity**: A row with up to 252 properties (1MB Storage, 2MB Cosmos)

## Core Patterns

### Create Table

```java
// Create table (throws if exists)
TableClient tableClient = serviceClient.createTable("mytable");

// Create if not exists (no exception)
TableClient tableClient = serviceClient.createTableIfNotExists("mytable");
```

### Get Table Client

```java
// From service client
TableClient tableClient = serviceClient.getTableClient("mytable");

// Direct construction
TableClient tableClient = new TableClientBuilder()
    .connectionString("<connection-string>")
    .tableName("mytable")
    .buildClient();
```

### Create Entity

```java
import com.azure.data.tables.models.TableEntity;

TableEntity entity = new TableEntity("partitionKey", "rowKey")
    .addProperty("Name", "Product A")
    .addProperty("Price", 29.99)
    .addProperty("Quantity", 100)
    .addProperty("IsAvailable", true);

tableClient.createEntity(entity);
```

### Get Entity

```java
TableEntity entity = tableClient.getEntity("partitionKey", "rowKey");

String name = (String) entity.getProperty("Name");
Double price = (Double) entity.getProperty("Price");
System.out.printf("Product: %s, Price: %.2f%n", name, price);
```

### Update Entity

```java
import com.azure.data.tables.models.TableEntityUpdateMode;

// Merge (update only specified properties)
TableEntity updateEntity = new TableEntity("partitionKey", "rowKey")
    .addProperty("Price", 24.99);
tableClient.updateEntity(updateEntity, TableEntityUpdateMode.MERGE);

// Replace (replace entire entity)
TableEntity replaceEntity = new TableEntity("partitionKey", "rowKey")
    .addProperty("Name", "Product A Updated")
    .addProperty("Price", 24.99)
    .addProperty("Quantity", 150);
tableClient.updateEntity(replaceEntity, TableEntityUpdateMode.REPLACE);
```

### Upsert Entity

```java
// Insert or update (merge mode)
tableClient.upsertEntity(entity, TableEntityUpdateMode.MERGE);

// Insert or replace
tableClient.upsertEntity(entity, TableEntityUpdateMode.REPLACE);
```

### Delete Entity

```java
tableClient.deleteEntity("partitionKey", "rowKey");
```

### List Entities

```java
import com.azure.data.tables.models.ListEntitiesOptions;

// List all entities
for (TableEntity entity : tableClient.listEntities()) {
    System.out.printf("%s - %s%n",
        entity.getPartitionKey(),
        entity.getRowKey());
}

// With filtering and selection
ListEntitiesOptions options = new ListEntitiesOptions()
    .setFilter("PartitionKey eq 'sales'")
    .setSelect("Name", "Price");

for (TableEntity entity : tableClient.listEntities(options, null, null)) {
    System.out.printf("%s: %.2f%n",
        entity.getProperty("Name"),
        entity.getProperty("Price"));
}
```

### Query with OData Filter

```java
// Filter by partition key
ListEntitiesOptions options = new ListEntitiesOptions()
    .setFilter("PartitionKey eq 'electronics'");

// Filter with multiple conditions
options.setFilter("PartitionKey eq 'electronics' and Price gt 100");

// Filter with comparison operators
options.setFilter("Quantity ge 10 and Quantity le 100");

// Top N results
options.setTop(10);

for (TableEntity entity : tableClient.listEntities(options, null, null)) {
    System.out.println(entity.getRowKey());
}
```

### Batch Operations (Transactions)

```java
import com.azure.data.tables.models.TableTransactionAction;
import com.azure.data.tables.models.TableTransactionActionType;
import java.util.Arrays;

// All entities must have same partition key
List<TableTransactionAction> actions = Arrays.asList(
    new TableTransactionAction(
        TableTransactionActionType.CREATE,
        new TableEntity("batch", "row1").addProperty("Name", "Item 1")),
    new TableTransactionAction(
        TableTransactionActionType.CREATE,
        new TableEntity("batch", "row2").addProperty("Name", "Item 2")),
    new TableTransactionAction(
        TableTransactionActionType.UPSERT_MERGE,
        new TableEntity("batch", "row3").addProperty("Name", "Item 3"))
);

tableClient.submitTransaction(actions);
```

### List Tables

```java
import com.azure.data.tables.models.TableItem;
import com.azure.data.tables.models.ListTablesOptions;

// List all tables
for (TableItem table : serviceClient.listTables()) {
    System.out.println(table.getName());
}

// Filter tables
ListTablesOptions options = new ListTablesOptions()
    .setFilter("TableName eq 'mytable'");

for (TableItem table : serviceClient.listTables(options, null, null)) {
    System.out.println(table.getName());
}
```

### Delete Table

```java
serviceClient.deleteTable("mytable");
```

## Typed Entities

```java
public class Product implements TableEntity {
    private String partitionKey;
    private String rowKey;
    private OffsetDateTime timestamp;
    private String eTag;
    private String name;
    private double price;
    
    // Getters and setters for all fields
    @Override
    public String getPartitionKey() { return partitionKey; }
    @Override
    public void setPartitionKey(String partitionKey) { this.partitionKey = partitionKey; }
    @Override
    public String getRowKey() { return rowKey; }
    @Override
    public void setRowKey(String rowKey) { this.rowKey = rowKey; }
    // ... other getters/setters
    
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public double getPrice() { return price; }
    public void setPrice(double price) { this.price = price; }
}

// Usage
Product product = new Product();
product.setPartitionKey("electronics");
product.setRowKey("laptop-001");
product.setName("Laptop");
product.setPrice(999.99);

tableClient.createEntity(product);
```

## Error Handling

```java
import com.azure.data.tables.models.TableServiceException;

try {
    tableClient.createEntity(entity);
} catch (TableServiceException e) {
    System.out.println("Status: " + e.getResponse().getStatusCode());
    System.out.println("Error: " + e.getMessage());
    // 409 = Conflict (entity exists)
    // 404 = Not Found
}
```

## Environment Variables

```bash
# Storage Account
AZURE_TABLES_CONNECTION_STRING=DefaultEndpointsProtocol=https;AccountName=...
AZURE_TABLES_ENDPOINT=https://<account>.table.core.windows.net

# Cosmos DB Table API
COSMOS_TABLE_ENDPOINT=https://<account>.table.cosmosdb.azure.com
```

## Best Practices

1. **Partition Key Design**: Choose keys that distribute load evenly
2. **Batch Operations**: Use transactions for atomic multi-entity updates
3. **Query Optimization**: Always filter by PartitionKey when possible
4. **Select Projection**: Only select needed properties for performance
5. **Entity Size**: Keep entities under 1MB (Storage) or 2MB (Cosmos)

## Trigger Phrases

- "Azure Tables Java"
- "table storage SDK"
- "Cosmos DB Table API"
- "NoSQL key-value storage"
- "partition key row key"
- "table entity CRUD"

## When to Use
This skill is applicable to execute the workflow or actions described in the overview.