Datasets Module Reference

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Module Components

Configuration Sections

Configuration Workflow

Pre-Defined Databases

Four system databases included in every solution:

SQLite databases are created automatically if they don't exist. Other database types must exist before connection.

Runtime Architecture

Service Architecture

• TRunModule.exe (Dataset) - Module process
• TServer - Database access services
• Client isolation - No direct database access
• Data virtualization - Abstract data sources

Process Separation

TRunModule.exe (Dataset) handles:

• Reading all dataset configurations
• Does NOT directly connect to databases
• Consumes TServer database services
• Manages tag mapping and updates

TServer provides:

• Actual database connections
• SQL execution services
• Connection pooling
• Transaction management

Request Processing

1. Client request (display/script)
2. Server routing
3. Database execution
4. Result propagation
5. Tag mapping

Threading Model

Dataset Module Thread:

• Main coordination thread
• Manages request queue
• Handles tag mapping

TServer Database Threads:

• One per DB connection
• Sequential execution per thread
• Connection isolation

Client Request Threads:

• Asynchronous request handling
• Non-blocking UI operations
• Parallel client support

Data Access Methods

Queries

SQL statements with dynamic parameters:

sql

SELECT * FROM Production 
WHERE BatchID = {{Tag.Batch_ID}}

Tables

Direct CRUD operations without SQL:

• Automatic schema management
• WhereCondition filtering
• Tag mapping

Files

Text-based data exchange:

• Recipe management
• Configuration import/export
• XML/ASCII/Unicode formats

Display Integration

DataGrid Control

xml

<DataGrid DataSource="{Dataset.Query.ProductionQuery}" />

Script Access

csharp

DataTable result = @Dataset.Query.MyQuery.SelectCommand();
@Tag.DataTableTag = result;

TK Methods

csharp

TK.CopyDataTableToTag(result, @Tag.Template);

Monitoring and Diagnostics

Runtime Monitoring

Access Datasets → Monitor during runtime:

• Operation status
• Row counts
• Error tracking
• Performance metrics

Namespace Properties

csharp

int status = @Dataset.Query.MyQuery.LastStatus;
string error = @Dataset.Query.MyQuery.LastStatusMessage;
int rows = @Dataset.Table.MyTable.RowCount;

Security and Administration

SQL Injection Prevention

• Use parameterized queries
• Avoid string concatenation
• Validate inputs
• Use stored procedures

The platform's parameterization:

• Treats all parameters as values, not code
• Prevents malicious SQL execution
• Maintains data type integrity
• Supports all major database platforms

Network Gateway

Configure ServerIP for secure access:

• Requires TWebServices
• Routes through gateway
• Isolates database

Time Zone Handling

• UTC storage default
• DateTimeMode configuration
• Local/UTC conversion

Error Handling

Error Detection

The module provides multiple error detection methods:

Property Monitoring:

csharp

@Dataset.Query.Query1.SelectCommand();
if (@Dataset.Query.Query1.Error != "") {
    // Handle error
}

Status Methods:

csharp

string status;
DataTable result = @Dataset.Query.Query1.SelectCommandWithStatusAsync(out status);
if (status != "OK") {
    // Handle error
}

Connection Failures

• Automatic retry logic
• Connection pooling recovery
• Error event propagation

Query Errors

• Exception capture in TServer
• Error property population
• Tag mapping skipped on error

Timeout Management

• Configurable command timeout
• Connection timeout settings
• Automatic cleanup

Troubleshooting

Common Issues

Connection Loss

• Check timeout settings
• Verify power settings
• Monitor network stability
• Review idle disconnect

Query Errors

• Validate SQL syntax
• Check table/column names
• Verify data types
• Test in database tool

Performance Issues

• Optimize queries
• Add indexes
• Reduce data volume
• Check network latency

Module Down

• Verify module running
• Check TServer status
• Review error logs

Database-Specific Syntax

Row Limiting Examples:

SQL Server:

sql

SELECT TOP 10 * FROM table

SQLite:

sql

SELECT * FROM table LIMIT 10

Oracle:

sql

SELECT * FROM table FETCH FIRST 10 ROWS ONLY

Oracle Limitations

NCHAR columns limited to 1999 bytes (auto-adjusted)

Best Practices Checklist

• Error Handling - Check LastStatus after operations
• Connection Testing - Use Test button before deployment
• Query Optimization - Design efficient SQL
• Schema Respect - Match DataTable to database
• Case Sensitivity - Use UPPER/LOWER for consistency
• Backup Strategy - Regular SQLite backups
• Performance Design - Consider all factors
• Prefer asynchronous - Use properties over methods
• Avoid UI blocking - No synchronous calls from screens
• Use appropriate domains - Client for user, Server for shared
• Pool connections - Reuse database connections
• Handle errors - Check status properties
• Monitor performance - Track execution times

Advanced Topics

→ [Dataset Engine (Reference)] - Internal operations

→ [Dataset DBs (Reference)] - Database connections

→ [Dataset Queries (Reference)] - SQL operations

→ [Dataset Tables (Reference)] - Direct table access

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