src/Sqlite/Library.fs

@@ -53,6 +53,21 @@ module Query =
             sprintf
                 "UPDATE %s SET data = json_patch(data, json(@data)) WHERE %s"
                 tableName (Query.whereByField fieldName op "@field")
+    
+    /// Queries to remove a field from a document
+    module RemoveField =
+        
+        /// Query to remove a field from a document by the document's ID
+        [<CompiledName "ById">]
+        let byId tableName =
+            $"""UPDATE %s{tableName} SET data = json_remove(data, @name) WHERE {Query.whereById "@id"}"""
+        
+        /// Query to remove a field from a document via a comparison on a JSON field within the document
+        [<CompiledName "ByField">]
+        let byField tableName fieldName op =
+            sprintf
+                "UPDATE %s SET data = json_remove(data, @name) WHERE %s"
+                tableName (Query.whereByField fieldName op "@field")
 
 
 /// Parameter handling helpers
@@ -74,6 +89,11 @@ module Parameters =
     let fieldParam (value: obj) =
         SqliteParameter("@field", value)
 
+    /// Create a JSON field name parameter (name "@name")
+    [<CompiledName "FieldName">]
+    let fieldNameParam name =
+        SqliteParameter("@name", $"$.%s{name}")
+
     /// An empty parameter sequence
     [<CompiledName "None">]
     let noParams =
@@ -315,6 +335,23 @@ module WithConn =
             Custom.nonQuery
                 (Query.Patch.byField tableName fieldName op) [ fieldParam value; jsonParam "@data" patch ] conn
 
+    /// Commands to remove fields from documents
+    [<RequireQualifiedAccess>]
+    module RemoveField =
+        
+        /// Remove a field from a document by the document's ID
+        [<CompiledName "ById">]
+        let byId tableName (docId: 'TKey) fieldName conn =
+            Custom.nonQuery (Query.RemoveField.byId tableName) [ idParam docId; fieldNameParam fieldName ] conn
+        
+        /// Remove a field from a document via a comparison on a JSON field in the document
+        [<CompiledName "ByField">]
+        let byField tableName whereFieldName op (value: obj) removeFieldName conn =
+            Custom.nonQuery
+                (Query.RemoveField.byField tableName whereFieldName op)
+                [ fieldParam value; fieldNameParam removeFieldName ]
+                conn
+        
     /// Commands to delete documents
     [<RequireQualifiedAccess>]
     module Delete =
@@ -522,6 +559,22 @@ module Patch =
         use conn = Configuration.dbConn ()
         WithConn.Patch.byField tableName fieldName op value patch conn
 
+/// Commands to remove fields from documents
+[<RequireQualifiedAccess>]
+module RemoveField =
+    
+    /// Remove a field from a document by the document's ID
+    [<CompiledName "ById">]
+    let byId tableName (docId: 'TKey) fieldName =
+        use conn = Configuration.dbConn ()
+        WithConn.RemoveField.byId tableName docId fieldName conn
+        
+    /// Remove a field from a document via a comparison on a JSON field in the document
+    [<CompiledName "ByField">]
+    let byField tableName whereFieldName op (value: obj) removeFieldName =
+        use conn = Configuration.dbConn ()
+        WithConn.RemoveField.byField tableName whereFieldName op value removeFieldName conn
+
 /// Commands to delete documents
 [<RequireQualifiedAccess>]
 module Delete =

src/Tests.CSharp/SqliteCSharpTests.cs

@@ -1,4 +1,5 @@
-using Expecto.CSharp;
+using System.Text.Json;
+using Expecto.CSharp;
 using Expecto;
 using Microsoft.Data.Sqlite;
 using Microsoft.FSharp.Core;
@@ -40,6 +41,21 @@ public static class SqliteCSharpTests
                         "UPDATE partial by JSON comparison query not correct");
                 })
             }),
+            TestList("RemoveField", new[]
+            {
+                TestCase("ById succeeds", () =>
+                {
+                    Expect.equal(Sqlite.Query.RemoveField.ById("tbl"),
+                        "UPDATE tbl SET data = json_remove(data, @name) WHERE data ->> 'Id' = @id",
+                        "Remove field by ID query not correct");
+                }),
+                TestCase("ByField succeeds", () =>
+                {
+                    Expect.equal(Sqlite.Query.RemoveField.ByField("tbl", "Fly", Op.LT),
+                        "UPDATE tbl SET data = json_remove(data, @name) WHERE data ->> 'Fly' < @field",
+                        "Remove field by field query not correct");
+                })
+            })
         }),
         TestList("Parameters", new[]
         {
@@ -540,6 +556,37 @@ public static class SqliteCSharpTests
                 })
             })
         }),
+        TestList("RemoveField", new[]
+        {
+            TestList("ById", new[]
+            {
+                TestCase("succeeds when a field is removed", async () =>
+                {
+                    await using var db = await SqliteDb.BuildDb();
+                    await LoadDocs();
+
+                    await RemoveField.ById(SqliteDb.TableName, "two", "Sub");
+                    var updated = await Find.ById<string, JsonDocument>(SqliteDb.TableName, "two");
+                    Expect.isNotNull(updated, "The updated document should have been retrieved");
+                    Expect.isNull(updated.Sub, "The sub-document should have been removed");
+                }),
+                TestCase("succeeds when a field is not removed", async () =>
+                {
+                    await using var db = await SqliteDb.BuildDb();
+                    await LoadDocs();
+                        
+                    // This not raising an exception is the test
+                    await RemoveField.ById(SqliteDb.TableName, "two", "AFieldThatIsNotThere");
+                }),
+                TestCase("succeeds when no document is matched", async () =>
+                {
+                    await using var db = await SqliteDb.BuildDb();
+                    
+                    // This not raising an exception is the test
+                    await RemoveField.ById(SqliteDb.TableName, "two", "Value");
+                })
+            })
+        }),
         TestList("Delete", new[]
         {
             TestList("ById", new[]

src/Tests/SqliteTests.fs

@@ -1,5 +1,6 @@
 module SqliteTests
 
+open System.Text.Json
 open BitBadger.Documents
 open BitBadger.Documents.Sqlite
 open BitBadger.Documents.Tests
@@ -31,6 +32,20 @@ let unitTests =
                         "UPDATE partial by JSON comparison query not correct"
                 }
             ]
+            testList "RemoveField" [
+                test "byId succeeds" {
+                    Expect.equal
+                        (Query.RemoveField.byId "tbl")
+                        "UPDATE tbl SET data = json_remove(data, @name) WHERE data ->> 'Id' = @id"
+                        "Remove field by ID query not correct"
+                }
+                test "byField succeeds" {
+                    Expect.equal
+                        (Query.RemoveField.byField "tbl" "Fly" GT)
+                        "UPDATE tbl SET data = json_remove(data, @name) WHERE data ->> 'Fly' > @field"
+                        "Remove field by field query not correct"
+                }
+            ]
         ]
         testList "Parameters" [
             test "idParam succeeds" {
@@ -489,6 +504,35 @@ let integrationTests =
                 }
             ]
         ]
+        testList "RemoveField" [
+            testList "byId" [
+                testTask "succeeds when a field is removed" {
+                    use! db = SqliteDb.BuildDb()
+                    do! loadDocs ()
+                    
+                    do! RemoveField.byId SqliteDb.TableName "two" "Sub"
+                    try
+                        let! _ = Find.byId<string, JsonDocument> SqliteDb.TableName "two"
+                        Expect.isTrue false "The updated document should have failed to parse"
+                    with
+                    | :? JsonException -> ()
+                    | exn as ex -> Expect.isTrue false $"Threw {ex.GetType().Name} ({ex.Message})"
+                }
+                testTask "succeeds when a field is not removed" {
+                    use! db = SqliteDb.BuildDb()
+                    do! loadDocs ()
+                    
+                    // This not raising an exception is the test
+                    do! RemoveField.byId SqliteDb.TableName "two" "AFieldThatIsNotThere"
+                }
+                testTask "succeeds when no document is matched" {
+                    use! db = SqliteDb.BuildDb()
+                    
+                    // This not raising an exception is the test
+                    do! RemoveField.byId SqliteDb.TableName "two" "Value"
+                }
+            ]
+        ]
         testList "Delete" [
             testList "byId" [
                 testTask "succeeds when a document is deleted" {