Functions/GenXdev.Data.SQLite/Get-SQLiteTableColumnData.cs
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// ################################################################################
// Part of PowerShell module : GenXdev.Data.SQLite // Original cmdlet filename : Get-SQLiteTableColumnData.cs // Original author : René Vaessen / GenXdev // Version : 1.302.2025 // ################################################################################ // Copyright (c) René Vaessen / GenXdev // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // ################################################################################ using System.Management.Automation; namespace GenXdev.Data.SQLite { /// <summary> /// <para type="synopsis"> /// Retrieves data from a specific column in a SQLite database table. /// </para> /// /// <para type="description"> /// This function provides a convenient way to extract data from a single column in a /// SQLite database table. It supports two connection methods: direct database file /// path or connection string. The function includes options to limit the number of /// returned records and uses proper SQLite query construction for optimal /// performance. /// </para> /// /// <para type="description"> /// PARAMETERS /// </para> /// /// <para type="description"> /// -ConnectionString <string><br/> /// The connection string to connect to the SQLite database. This parameter is /// mutually exclusive with DatabaseFilePath.<br/> /// - <b>Position</b>: 0<br/> /// - <b>ParameterSet</b>: ConnectionString<br/> /// - <b>Mandatory</b>: true<br/> /// </para> /// /// <para type="description"> /// -DatabaseFilePath <string><br/> /// The file path to the SQLite database file. This parameter is mutually exclusive /// with ConnectionString.<br/> /// - <b>Position</b>: 0<br/> /// - <b>ParameterSet</b>: DatabaseFilePath<br/> /// - <b>Mandatory</b>: true<br/> /// </para> /// /// <para type="description"> /// -TableName <string><br/> /// The name of the table from which to retrieve the column data.<br/> /// - <b>Position</b>: 1<br/> /// - <b>Mandatory</b>: true<br/> /// </para> /// /// <para type="description"> /// -ColumnName <string><br/> /// The name of the column whose data should be retrieved.<br/> /// - <b>Position</b>: 2<br/> /// - <b>Mandatory</b>: true<br/> /// </para> /// /// <para type="description"> /// -Count <int><br/> /// The maximum number of records to return. Default is 100. Use -1 to return all /// records without limit.<br/> /// - <b>Position</b>: 3<br/> /// - <b>Default</b>: 100<br/> /// </para> /// /// <example> /// <para>Get-SQLiteTableColumnData -DatabaseFilePath "C:\MyDb.sqlite" -TableName "Employees" -ColumnName "Email" -Count 10</para> /// <para>Retrieves up to 10 email addresses from the Employees table in the specified SQLite database.</para> /// <code> /// Get-SQLiteTableColumnData -DatabaseFilePath "C:\MyDb.sqlite" ` /// -TableName "Employees" ` /// -ColumnName "Email" ` /// -Count 10 /// </code> /// </example> /// /// <example> /// <para>Get-SQLiteTableColumnData "C:\MyDb.sqlite" "Employees" "Email"</para> /// <para>Retrieves email addresses from the Employees table using positional parameters.</para> /// <code> /// Get-SQLiteTableColumnData "C:\MyDb.sqlite" "Employees" "Email" /// </code> /// </example> /// </summary> [Cmdlet(VerbsCommon.Get, "SQLiteTableColumnData")] [OutputType(typeof(object))] public class GetSQLiteTableColumnDataCommand : PSGenXdevCmdlet { /// <summary> /// The connection string to connect to the SQLite database /// </summary> [Parameter( Position = 0, Mandatory = true, ParameterSetName = "ConnectionString", HelpMessage = "The connection string to the SQLite database")] [ValidateNotNullOrEmpty] public string ConnectionString { get; set; } /// <summary> /// The path to the SQLite database file /// </summary> [Parameter( Position = 0, Mandatory = true, ParameterSetName = "DatabaseFilePath", HelpMessage = "The path to the SQLite database file")] [ValidateNotNullOrEmpty] public string DatabaseFilePath { get; set; } /// <summary> /// The name of the table to query /// </summary> [Parameter( Position = 1, Mandatory = true, HelpMessage = "The name of the table to query")] [ValidateNotNullOrEmpty] public string TableName { get; set; } /// <summary> /// The name of the column to retrieve /// </summary> [Parameter( Position = 2, Mandatory = true, HelpMessage = "The name of the column to retrieve")] [ValidateNotNullOrEmpty] public string ColumnName { get; set; } /// <summary> /// Number of records to return. Default 100. Use -1 for all /// </summary> [Parameter( Position = 3, Mandatory = false, HelpMessage = "Number of records to return. Default 100. Use -1 for all")] public int Count { get; set; } = 100; /// <summary> /// Begin processing - initialization logic /// </summary> protected override void BeginProcessing() { // Log the start of the operation with table and column details WriteVerbose($"Starting data retrieval for column '{ColumnName}' from table '{TableName}'"); } /// <summary> /// Process record - main cmdlet logic /// </summary> protected override void ProcessRecord() { // Construct the appropriate SQL query based on whether a limit is needed string query; if (Count == -1) { query = $"SELECT {ColumnName} FROM {TableName}"; } else { query = $"SELECT {ColumnName} FROM {TableName} LIMIT {Count}"; } // Log the constructed query for debugging WriteVerbose($"Executing SQL query: {query}"); // Prepare parameters for Invoke-SQLiteQuery and execute the query // Use ScriptBlock.Create with parameters to safely pass values var scriptBlock = ScriptBlock.Create(@" param($ConnectionString, $DatabaseFilePath, $TableName, $ColumnName, $Count, $Queries) GenXdev.Data\Invoke-SQLiteQuery -ConnectionString $ConnectionString -DatabaseFilePath $DatabaseFilePath -TableName $TableName -ColumnName $ColumnName -Count $Count -Queries $Queries "); // Create parameter dictionary for the script block var parameters = new object[] { ConnectionString, DatabaseFilePath, TableName, ColumnName, Count, query }; // Execute the script block and write results var results = scriptBlock.Invoke(parameters); foreach (var result in results) { WriteObject(result); } } /// <summary> /// End processing - cleanup logic /// </summary> protected override void EndProcessing() { // Log completion of the operation WriteVerbose("Column data retrieval completed successfully"); } } } |