From 0ed07e70a061e4c2c93d36856c67eb289c844f0d Mon Sep 17 00:00:00 2001 From: KB Bot Date: Wed, 16 Oct 2024 05:49:46 +0000 Subject: [PATCH 1/7] Added new kb article grid-convert-descriptors-to-sql --- .../grid-convert-descriptors-to-sql.md | 207 ++++++++++++++++++ 1 file changed, 207 insertions(+) create mode 100644 knowledge-base/grid-convert-descriptors-to-sql.md diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md new file mode 100644 index 0000000000..1e838ec90a --- /dev/null +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -0,0 +1,207 @@ +--- +title: Converting Filter and Sort Descriptors to SQL Queries in Blazor Grid +description: Learn how to parse filter and sort descriptors from the Blazor Grid into SQL query statements for manual SQL queries execution using the OnRead event. +type: how-to +page_title: How to Parse Blazor Grid Descriptors into SQL Query Statements +slug: grid-convert-descriptors-to-sql +tags: grid, blazor, filter descriptors , sort descriptors, SQL query +res_type: kb +ticketid: 1666625, 1653361 +--- + +## Environment + + + + + + + + +
ProductGrid for Blazor
+ +## Description + +When using the Grid [`OnRead` event]({%slug grid-events%}#read-event) to execute SQL queries, I need to convert the Grid's filter and sort descriptors into SQL query statements. This way I can create SQL clauses for filtering and ordering items directly through SQL. + +This KB article also answers the following questions: +- How can I convert Grid filters and sorters to SQL WHERE and ORDER BY clauses? +- Is there a way to parse Grid filter and sort descriptors into SQL queries? +- Can I use `DataSourceRequest`({%slug common-features-data-binding-onread%}#event-argument) to generate SQL query statements for filtering and sorting? + +## Solution + +To convert the Grid's filter and sort descriptors into SQL query statements, you need to manually construct the SQL query within the `OnRead` event handler by utilizing the `args.Request.Filters` and `args.Request.Sorts` objects. Although Telerik UI for Blazor does not provide a direct method to extract the SQL query from the `DataSourceRequest`, a manual approach can be adopted. + +The following steps outline how to achieve this: + +1. **Handle the `OnRead` Event**: Add an `OnRead` event to your Grid and in the event handler, access the `args.Request.Filters` and `args.Request.Sorts` to construct your SQL query. + +2. **Parse Filters**: Iterate through `args.Request.Filters` to construct the WHERE clause of your SQL query. Each filter in this collection will correspond to a column filter in the Grid. + +3. **Parse Sort Descriptors**: Similarly, iterate through `args.Request.Sorts` to build the ORDER BY clause of your SQL query. Each sort descriptor corresponds to a column sorting in the Grid. + +4. **Execute SQL Query**: With the constructed WHERE and ORDER BY clauses, form your complete SQL query and execute it against your database. + +5. **Set Grid Data**: Finally, assign the result of your SQL query to the Grid by setting `args.Data`. + +## Example + +Below is a simplified example demonstrating how to parse filter and sort descriptors. This example does not directly execute a SQL query but outlines how to construct the WHERE and ORDER BY clauses. + +```csharp +@using System.Text +@using Telerik.DataSource +@using Telerik.DataSource.Extensions + + + + + + + + + +@code { + private List GridData { get; set; } + + private string SqlQuery { get; set; } + private string FilterQuery { get; set; } + private string SortQuery { get; set; } + + private async Task ReadItems(GridReadEventArgs args) + { + FilterQuery = BuildFilterQuery(args.Request.Filters); + SortQuery = BuildSortQuery(args.Request.Sorts); + + if (FilterQuery != string.Empty) + { + SqlQuery = $"SELECT * FROM MyTable WHERE {FilterQuery}"; + + GridData = await ExecuteSqlQuery(SqlQuery); + } + else if (SortQuery != string.Empty) + { + SqlQuery = $"SELECT * FROM MyTable ORDER BY {SortQuery}"; + + GridData = await ExecuteSqlQuery(SqlQuery); + } + else + { + GridData = GenerateData(); + } + + var datasourceResult = GridData.ToDataSourceResult(args.Request); + + args.Data = datasourceResult.Data; + args.Total = datasourceResult.Total; + } + + private string BuildFilterQuery(IEnumerable filters) + { + // Implement logic to parse filters into SQL WHERE clause + // Example: "Name = 'John' AND Age > 30" + // You may need to adjust the SQL query depending if there are + // more FilterDescriptors (when using FilterMenu filter mode) + var filterQuery = new StringBuilder(); + foreach (var filter in filters) + { + if (filter is CompositeFilterDescriptor compositeFilter) + { + foreach (var childFilter in compositeFilter.FilterDescriptors) + { + filterQuery.Append(ParseFilterDescriptor(childFilter)); + } + } + } + return filterQuery.ToString(); + } + + private string ParseFilterDescriptor(IFilterDescriptor filter) + { + if (filter is FilterDescriptor descriptor) + { + return $"{descriptor.Member} {GetSqlOperator(descriptor.Operator)} '{descriptor.Value}'"; + } + return string.Empty; + } + + private string GetSqlOperator(FilterOperator filterOperator) + { + return filterOperator switch + { + FilterOperator.IsEqualTo => "=", + FilterOperator.IsNotEqualTo => "<>", + FilterOperator.IsGreaterThan => ">", + FilterOperator.IsGreaterThanOrEqualTo => ">=", + FilterOperator.IsLessThan => "<", + FilterOperator.IsLessThanOrEqualTo => "<=", + FilterOperator.Contains => "LIKE", + _ => throw new NotSupportedException($"Operator {filterOperator} is not supported") + }; + } + + private string BuildSortQuery(IEnumerable sorts) + { + // Implement logic to parse sorters into SQL ORDER BY clause + // Example: "Name ASC" + return string.Join(", ", sorts.Select(s => $"{s.Member} {(s.SortDirection == ListSortDirection.Ascending ? "ASC" : "DESC")}")); + } + + private async Task> ExecuteSqlQuery(string sqlQuery) + { + // Implement logic to execute the SQL query and return the result + // This is a placeholder for your actual data access code + if (FilterQuery != string.Empty) + { + } + + if (SortQuery != string.Empty) + { + } + //Remove this line when you execute the SQL query + //It is only for example purposes + GridData = new List(); + return GridData; + } + + protected override void OnInitialized() + { + GridData = GenerateData(); + } + + private List GenerateData() + { + var result = new List(); + var rand = new Random(); + for (int i = 0; i < 100; i++) + { + result.Add(new MyItem() + { + ID = i, + Name = "Name " + i, + Age = rand.Next(10, 40) + }); + } + + return result; + } + + public class MyItem + { + public int ID { get; set; } + public string Name { get; set; } + public int Age { get; set; } + } +} +``` + +## See Also + +- [OnRead Event Documentation]({%slug grid-events%}#read-event) +- [Forum Post on Using DataSourceRequest in SQL Query](https://www.telerik.com/forums/can-datasourcerequest-be-used-in-sql-query-to-add-where-and-order-by-clauses) +- [Get Information From the DataSourceRequest]({%slug components/grid/manual-operations%}#get-information-from-the-datasourcerequest) From dfeaaf982eaa8dea2fb96f76453eb4a7e8ca8dd9 Mon Sep 17 00:00:00 2001 From: NansiYancheva Date: Wed, 16 Oct 2024 11:05:40 +0300 Subject: [PATCH 2/7] update slug --- knowledge-base/grid-convert-descriptors-to-sql.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md index 1e838ec90a..1f9097a207 100644 --- a/knowledge-base/grid-convert-descriptors-to-sql.md +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -27,7 +27,7 @@ When using the Grid [`OnRead` event]({%slug grid-events%}#read-event) to execute This KB article also answers the following questions: - How can I convert Grid filters and sorters to SQL WHERE and ORDER BY clauses? - Is there a way to parse Grid filter and sort descriptors into SQL queries? -- Can I use `DataSourceRequest`({%slug common-features-data-binding-onread%}#event-argument) to generate SQL query statements for filtering and sorting? +- Can I use [`DataSourceRequest`]({%slug common-features-data-binding-onread%}#event-argument) to generate SQL query statements for filtering and sorting? ## Solution From 375f857b371983027746c7e1bc61956b16a4af84 Mon Sep 17 00:00:00 2001 From: NansiYancheva <106161782+NansiYancheva@users.noreply.github.com> Date: Thu, 17 Oct 2024 08:48:46 +0300 Subject: [PATCH 3/7] Update knowledge-base/grid-convert-descriptors-to-sql.md Co-authored-by: Iva Stefanova Koevska-Atanasova --- knowledge-base/grid-convert-descriptors-to-sql.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md index 1f9097a207..5393e90236 100644 --- a/knowledge-base/grid-convert-descriptors-to-sql.md +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -31,7 +31,7 @@ This KB article also answers the following questions: ## Solution -To convert the Grid's filter and sort descriptors into SQL query statements, you need to manually construct the SQL query within the `OnRead` event handler by utilizing the `args.Request.Filters` and `args.Request.Sorts` objects. Although Telerik UI for Blazor does not provide a direct method to extract the SQL query from the `DataSourceRequest`, a manual approach can be adopted. +To convert the Grid's filter and sort descriptors into SQL query statements, you need to manually construct the SQL query within the `OnRead` event handler by utilizing the `args.Request.Filters` and `args.Request.Sorts` objects. Although Telerik UI for Blazor does not provide a direct method to extract the SQL query from the `DataSourceRequest`, you can achieve this manually. The following steps outline how to achieve this: From ee48c0966583cb367257987799725a60b2969e5c Mon Sep 17 00:00:00 2001 From: NansiYancheva <106161782+NansiYancheva@users.noreply.github.com> Date: Thu, 17 Oct 2024 08:48:53 +0300 Subject: [PATCH 4/7] Update knowledge-base/grid-convert-descriptors-to-sql.md Co-authored-by: Iva Stefanova Koevska-Atanasova --- knowledge-base/grid-convert-descriptors-to-sql.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md index 5393e90236..7e53a85d06 100644 --- a/knowledge-base/grid-convert-descriptors-to-sql.md +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -25,7 +25,7 @@ ticketid: 1666625, 1653361 When using the Grid [`OnRead` event]({%slug grid-events%}#read-event) to execute SQL queries, I need to convert the Grid's filter and sort descriptors into SQL query statements. This way I can create SQL clauses for filtering and ordering items directly through SQL. This KB article also answers the following questions: -- How can I convert Grid filters and sorters to SQL WHERE and ORDER BY clauses? +- How can I convert Grid filters and sorters to SQL `WHERE` and `ORDER BY` clauses? - Is there a way to parse Grid filter and sort descriptors into SQL queries? - Can I use [`DataSourceRequest`]({%slug common-features-data-binding-onread%}#event-argument) to generate SQL query statements for filtering and sorting? From 67ab6f3dc23409447683160674eb55cfcf7b5968 Mon Sep 17 00:00:00 2001 From: NansiYancheva Date: Thu, 17 Oct 2024 09:00:26 +0300 Subject: [PATCH 5/7] update after review --- .../grid-convert-descriptors-to-sql.md | 20 ++++++++----------- 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md index 7e53a85d06..c3d9e02f64 100644 --- a/knowledge-base/grid-convert-descriptors-to-sql.md +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -22,7 +22,7 @@ ticketid: 1666625, 1653361 ## Description -When using the Grid [`OnRead` event]({%slug grid-events%}#read-event) to execute SQL queries, I need to convert the Grid's filter and sort descriptors into SQL query statements. This way I can create SQL clauses for filtering and ordering items directly through SQL. +When using the Grid [`OnRead` event]({%slug grid-events%}#read-event) to execute SQL queries, I need to convert the Grid's filter and sort descriptors into SQL query statements. This way I can create SQL clauses for filtering and ordering items directly through SQL. This KB article also answers the following questions: - How can I convert Grid filters and sorters to SQL `WHERE` and `ORDER BY` clauses? @@ -31,23 +31,19 @@ This KB article also answers the following questions: ## Solution -To convert the Grid's filter and sort descriptors into SQL query statements, you need to manually construct the SQL query within the `OnRead` event handler by utilizing the `args.Request.Filters` and `args.Request.Sorts` objects. Although Telerik UI for Blazor does not provide a direct method to extract the SQL query from the `DataSourceRequest`, you can achieve this manually. +To convert the Grid's filter and sort descriptors into SQL query statements, you need to manually construct the SQL query within the `OnRead` event handler by utilizing the `args.Request.Filters` and `args.Request.Sorts` objects. Although Telerik UI for Blazor does not provide a direct method to extract the SQL query from the `DataSourceRequest`, you can achieve this manually. The following steps outline how to achieve this: -1. **Handle the `OnRead` Event**: Add an `OnRead` event to your Grid and in the event handler, access the `args.Request.Filters` and `args.Request.Sorts` to construct your SQL query. - -2. **Parse Filters**: Iterate through `args.Request.Filters` to construct the WHERE clause of your SQL query. Each filter in this collection will correspond to a column filter in the Grid. - -3. **Parse Sort Descriptors**: Similarly, iterate through `args.Request.Sorts` to build the ORDER BY clause of your SQL query. Each sort descriptor corresponds to a column sorting in the Grid. - -4. **Execute SQL Query**: With the constructed WHERE and ORDER BY clauses, form your complete SQL query and execute it against your database. - -5. **Set Grid Data**: Finally, assign the result of your SQL query to the Grid by setting `args.Data`. +1. Add an `OnRead` event to your Grid and in the event handler, access the `args.Request.Filters` and `args.Request.Sorts` to construct your SQL query. +1. Iterate through `args.Request.Filters` to construct the `WHERE` clause of your SQL query. Each filter in this collection will correspond to a column filter in the Grid. +1. Iterate through `args.Request.Sorts` to build the `ORDER BY` clause of your SQL query. Each sort descriptor corresponds to a column sorting in the Grid. +1. Form your complete SQL query and execute it against your database with the constructed `WHERE` and `ORDER BY` clauses. +1. Assign the result of your SQL query to the Grid by setting `args.Data`. ## Example -Below is a simplified example demonstrating how to parse filter and sort descriptors. This example does not directly execute a SQL query but outlines how to construct the WHERE and ORDER BY clauses. +Below is a simplified example demonstrating how to parse filter and sort descriptors. This example does not directly execute a SQL query but outlines how to construct the `WHERE` and `ORDER BY` clauses. ```csharp @using System.Text From 340cd36997ef49590b64005995df1cb0fa38c6a7 Mon Sep 17 00:00:00 2001 From: NansiYancheva <106161782+NansiYancheva@users.noreply.github.com> Date: Thu, 17 Oct 2024 18:45:38 +0300 Subject: [PATCH 6/7] Update knowledge-base/grid-convert-descriptors-to-sql.md Co-authored-by: Dimo Dimov <961014+dimodi@users.noreply.github.com> --- knowledge-base/grid-convert-descriptors-to-sql.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md index c3d9e02f64..db31f96a5f 100644 --- a/knowledge-base/grid-convert-descriptors-to-sql.md +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -63,7 +63,7 @@ Below is a simplified example demonstrating how to parse filter and sort descrip @code { - private List GridData { get; set; } + private List GridData { get; set; } = new(); private string SqlQuery { get; set; } private string FilterQuery { get; set; } From 2e94c3773b6bd83cf9a960961931beb1652e88fe Mon Sep 17 00:00:00 2001 From: NansiYancheva Date: Thu, 17 Oct 2024 18:55:35 +0300 Subject: [PATCH 7/7] update example --- .../grid-convert-descriptors-to-sql.md | 31 +++++++------------ 1 file changed, 11 insertions(+), 20 deletions(-) diff --git a/knowledge-base/grid-convert-descriptors-to-sql.md b/knowledge-base/grid-convert-descriptors-to-sql.md index db31f96a5f..0a3fe99978 100644 --- a/knowledge-base/grid-convert-descriptors-to-sql.md +++ b/knowledge-base/grid-convert-descriptors-to-sql.md @@ -65,26 +65,23 @@ Below is a simplified example demonstrating how to parse filter and sort descrip @code { private List GridData { get; set; } = new(); - private string SqlQuery { get; set; } - private string FilterQuery { get; set; } - private string SortQuery { get; set; } - private async Task ReadItems(GridReadEventArgs args) { - FilterQuery = BuildFilterQuery(args.Request.Filters); - SortQuery = BuildSortQuery(args.Request.Sorts); + string sqlQuery = string.Empty; + string filterQuery = BuildFilterQuery(args.Request.Filters); + string sortQuery = BuildSortQuery(args.Request.Sorts); - if (FilterQuery != string.Empty) + if (filterQuery != string.Empty) { - SqlQuery = $"SELECT * FROM MyTable WHERE {FilterQuery}"; - - GridData = await ExecuteSqlQuery(SqlQuery); + sqlQuery = $"SELECT * FROM MyTable WHERE {filterQuery}"; + + GridData = await ExecuteSqlQuery(sqlQuery); } - else if (SortQuery != string.Empty) + else if (sortQuery != string.Empty) { - SqlQuery = $"SELECT * FROM MyTable ORDER BY {SortQuery}"; - - GridData = await ExecuteSqlQuery(SqlQuery); + sqlQuery = $"SELECT * FROM MyTable ORDER BY {sortQuery}"; + + GridData = await ExecuteSqlQuery(sqlQuery); } else { @@ -152,13 +149,7 @@ Below is a simplified example demonstrating how to parse filter and sort descrip { // Implement logic to execute the SQL query and return the result // This is a placeholder for your actual data access code - if (FilterQuery != string.Empty) - { - } - if (SortQuery != string.Empty) - { - } //Remove this line when you execute the SQL query //It is only for example purposes GridData = new List();