Add ability to run SQL queries

Author: Les Melnychuk

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXDatabaseManager.h

@@ -12,16 +12,23 @@
 //  which Flying Meat Inc. licenses this file to you.
 
 #import <Foundation/Foundation.h>
+#import "FLEXSQLResult.h"
 
 @protocol FLEXDatabaseManager <NSObject>
 
 @required
+
 + (instancetype)managerForDatabase:(NSString *)path;
 
 - (BOOL)open;
+
 /// @return a list of all table names
 - (NSArray<NSString *> *)queryAllTables;
-- (NSArray<NSString *> *)queryAllColumnsWithTableName:(NSString *)tableName;
-- (NSArray<NSArray *> *)queryAllDataWithTableName:(NSString *)tableName;
+- (NSArray<NSString *> *)queryAllColumnsOfTable:(NSString *)tableName;
+- (NSArray<NSArray *> *)queryAllDataInTable:(NSString *)tableName;
+
+@optional
+
+- (FLEXSQLResult *)executeStatement:(NSString *)SQLStatement;
 
 @end

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXRealmDatabaseManager.m

@@ -8,6 +8,7 @@
 
 #import "FLEXRealmDatabaseManager.h"
 #import "NSArray+Functional.h"
+#import "FLEXSQLResult.h"
 
 #if __has_include(<Realm/Realm.h>)
 #import <Realm/Realm.h>
@@ -68,15 +69,15 @@ - (BOOL)open {
     }];
 }
 
-- (NSArray<NSString *> *)queryAllColumnsWithTableName:(NSString *)tableName {
+- (NSArray<NSString *> *)queryAllColumnsOfTable:(NSString *)tableName {
     RLMObjectSchema *objectSchema = [self.realm.schema schemaForClassName:tableName];
     // Map each column to its name
     return [objectSchema.properties flex_mapped:^id(RLMProperty *property, NSUInteger idx) {
         return property.name;
     }];
 }
 
-- (NSArray<NSArray *> *)queryAllDataWithTableName:(NSString *)tableName {
+- (NSArray<NSArray *> *)queryAllDataInTable:(NSString *)tableName {
     RLMObjectSchema *objectSchema = [self.realm.schema schemaForClassName:tableName];
     RLMResults *results = [self.realm allObjects:tableName];
     if (results.count == 0 || !objectSchema) {

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXSQLResult.h

@@ -0,0 +1,41 @@
+//
+//  FLEXSQLResult.h
+//  FLEX
+//
+//  Created by Tanner on 3/3/20.
+//  Copyright © 2020 Flipboard. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FLEXSQLResult : NSObject
+
+/// Describes the result of a non-select query, or an error of any kind of query
++ (instancetype)message:(NSString *)message;
+/// @param rowData A list of rows, where each element in the row
+/// corresponds to the column given in /c columnNames
++ (instancetype)columns:(NSArray<NSString *> *)columnNames
+                rows:(NSArray<NSArray<NSString *> *> *)rowData;
+
+@property (nonatomic, readonly, nullable) NSString *message;
+
+/// A list of column names
+@property (nonatomic, readonly, nullable) NSArray<NSString *> *columns;
+/// A list of rows, where each element in the row corresponds
+/// to the value of the column at the same index in \c columns.
+///
+/// That is, given a row, looping over the contents of the row and
+/// the contents of \c columns will give you key-value pairs of
+/// column names to column values for that row.
+@property (nonatomic, readonly, nullable) NSArray<NSArray<NSString *> *> *rows;
+/// A list of rows where the fields are paired to column names.
+///
+/// This property is lazily constructed by looping over
+/// the rows and columns present in the other two properties.
+@property (nonatomic, readonly, nullable) NSArray<NSDictionary<NSString *, id> *> *keyedRows;
+
+@end
+
+NS_ASSUME_NONNULL_END

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXSQLResult.m

@@ -0,0 +1,47 @@
+//
+//  FLEXSQLResult.m
+//  FLEX
+//
+//  Created by Tanner on 3/3/20.
+//  Copyright © 2020 Flipboard. All rights reserved.
+//
+
+#import "FLEXSQLResult.h"
+#import "NSArray+Functional.h"
+
+@implementation FLEXSQLResult
+@synthesize keyedRows = _keyedRows;
+
++ (instancetype)message:(NSString *)message {
+    return [[self alloc] initWithmessage:message columns:nil rows:nil];
+}
+
++ (instancetype)columns:(NSArray<NSString *> *)columnNames rows:(NSArray<NSArray<NSString *> *> *)rowData {
+    return [[self alloc] initWithmessage:nil columns:columnNames rows:rowData];
+}
+
+- (id)initWithmessage:(NSString *)message columns:(NSArray *)columns rows:(NSArray<NSArray *> *)rows {
+    NSParameterAssert(message || (columns && rows));
+    NSParameterAssert(columns.count == rows.firstObject.count);
+    
+    self = [super init];
+    if (self) {
+        _message = message;
+        _columns = columns;
+        _rows = rows;
+    }
+    
+    return self;
+}
+
+- (NSArray<NSDictionary<NSString *,id> *> *)keyedRows {
+    if (!_keyedRows) {
+        _keyedRows = [self.rows flex_mapped:^id(NSArray<NSString *> *row, NSUInteger idx) {
+            return [NSDictionary dictionaryWithObjects:row forKeys:self.columns];
+        }];
+    }
+    
+    return _keyedRows;
+}
+
+@end

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXSQLiteDatabaseManager.m

@@ -9,12 +9,13 @@
 #import "FLEXSQLiteDatabaseManager.h"
 #import "FLEXManager.h"
 #import "NSArray+Functional.h"
+#import "FLEXSQLResult.h"
 #import <sqlite3.h>
 
-static NSString * const QUERY_TABLENAMES_SQL = @"SELECT name FROM sqlite_master WHERE type='table' ORDER BY name";
+static NSString * const QUERY_TABLENAMES = @"SELECT name FROM sqlite_master WHERE type='table' ORDER BY name";
 
 @interface FLEXSQLiteDatabaseManager ()
-@property (nonatomic, readonly) sqlite3 *db;
+@property (nonatomic) sqlite3 *db;
 @property (nonatomic, copy) NSString *path;
 @end
 
@@ -36,7 +37,7 @@ - (instancetype)initWithPath:(NSString *)path {
 }
 
 - (BOOL)open {
-    if (_db) {
+    if (self.db) {
         return YES;
     }
 
@@ -57,9 +58,9 @@ - (BOOL)open {
 
     return YES;
 }
-
+    
 - (BOOL)close {
-    if (!_db) {
+    if (!self.db) {
         return YES;
     }
 
@@ -84,88 +85,85 @@ - (BOOL)close {
         }
     } while (retry);
 
-    _db = nil;
+    self.db = nil;
     return YES;
 }
 
 - (NSArray<NSString *> *)queryAllTables {
-    return [[self executeQuery:QUERY_TABLENAMES_SQL] flex_mapped:^id(NSArray *table, NSUInteger idx) {
+    return [[self executeStatement:QUERY_TABLENAMES].rows flex_mapped:^id(NSArray *table, NSUInteger idx) {
         return table.firstObject;
     }];
 }
 
-- (NSArray<NSString *> *)queryAllColumnsWithTableName:(NSString *)tableName {
+- (NSArray<NSString *> *)queryAllColumnsOfTable:(NSString *)tableName {
     NSString *sql = [NSString stringWithFormat:@"PRAGMA table_info('%@')",tableName];
-    NSArray<NSDictionary *> *results =  [self executeQueryWithColumns:sql];
+    FLEXSQLResult *results = [self executeStatement:sql];
 
-    return [results flex_mapped:^id(NSDictionary *column, NSUInteger idx) {
+    return [results.keyedRows flex_mapped:^id(NSDictionary *column, NSUInteger idx) {
         return column[@"name"];
     }];
 }
 
-- (NSArray<NSArray *> *)queryAllDataWithTableName:(NSString *)tableName {
-    return [self executeQuery:[@"SELECT * FROM "
+- (NSArray<NSArray *> *)queryAllDataInTable:(NSString *)tableName {
+    return [self executeStatement:[@"SELECT * FROM "
         stringByAppendingString:tableName
-    ]];
+    ]].rows;
 }
 
-#pragma mark - Private
-
-/// @return an array of rows, where each row is an array
-/// containing the values of each column for that row
-- (NSArray<NSArray *> *)executeQuery:(NSString *)sql {
+- (FLEXSQLResult *)executeStatement:(NSString *)sql {
     [self open];
 
-    NSMutableArray<NSArray *> *results = [NSMutableArray array];
+    FLEXSQLResult *result = nil;
 
     sqlite3_stmt *pstmt;
     if (sqlite3_prepare_v2(_db, sql.UTF8String, -1, &pstmt, 0) == SQLITE_OK) {
-        while (sqlite3_step(pstmt) == SQLITE_ROW) {
-            int num_cols = sqlite3_data_count(pstmt);
-            if (num_cols > 0) {
-                int columnCount = sqlite3_column_count(pstmt);
-                
-                [results addObject:[NSArray flex_forEachUpTo:columnCount map:^id(NSUInteger i) {
+        NSMutableArray<NSArray *> *rows = [NSMutableArray new];
+        
+        // Grab columns
+        int columnCount = sqlite3_column_count(pstmt);
+        NSArray<NSString *> *columns = [NSArray flex_forEachUpTo:columnCount map:^id(NSUInteger i) {
+            return @(sqlite3_column_name(pstmt, (int)i));
+        }];
+        
+        // Execute statement
+        int status;
+        while ((status = sqlite3_step(pstmt)) == SQLITE_ROW) {
+            // Grab rows if this is a selection query
+            int dataCount = sqlite3_data_count(pstmt);
+            if (dataCount > 0) {
+                [rows addObject:[NSArray flex_forEachUpTo:columnCount map:^id(NSUInteger i) {
                     return [self objectForColumnIndex:(int)i stmt:pstmt];
                 }]];
             }
         }
-    }
-    
-    [self close];
-    return results;
-}
-
-/// Like \c executeQuery: except that a list of dictionaries are returned,
-/// where the keys are column names and the values are the data.
-- (NSArray<NSDictionary *> *)executeQueryWithColumns:(NSString *)sql {
-    [self open];
-    
-    NSMutableArray<NSDictionary *> *results = [NSMutableArray array];
-    
-    sqlite3_stmt *pstmt;
-    if (sqlite3_prepare_v2(_db, sql.UTF8String, -1, &pstmt, 0) == SQLITE_OK) {
-        while (sqlite3_step(pstmt) == SQLITE_ROW) {
-            int num_cols = sqlite3_data_count(pstmt);
-            if (num_cols > 0) {
-                int columnCount = sqlite3_column_count(pstmt);
-                
-                
-                NSMutableDictionary *rowFields = [NSMutableDictionary new];
-                for (int i = 0; i < columnCount; i++) {
-                    id value = [self objectForColumnIndex:(int)i stmt:pstmt];
-                    rowFields[@(sqlite3_column_name(pstmt, i))] = value;
-                }
-                
-                [results addObject:rowFields];
+        
+        if (status == SQLITE_DONE) {
+            if (rows.count) {
+                // We selected some rows
+                result = [FLEXSQLResult columns:columns rows:rows];
+            } else {
+                // We executed a query like INSERT, UDPATE, or DELETE
+                int rowsAffected = sqlite3_changes(_db);
+                NSString *message = [NSString stringWithFormat:@"%d row(s) affected", rowsAffected];
+                result = [FLEXSQLResult message:message];
             }
+        } else {
+            // An error occured executing the query
+            result = [FLEXSQLResult message:@(sqlite3_errmsg(_db) ?: "(Execution: empty error)")];
         }
+    } else {
+        // An error occurred creating the prepared statement
+        result = [FLEXSQLResult message:@(sqlite3_errmsg(_db) ?: "(Prepared statement: empty error)")];
     }
 
+    sqlite3_finalize(pstmt);
     [self close];
-    return results;
+    return result;
 }
 
+
+#pragma mark - Private
+
 - (id)objectForColumnIndex:(int)columnIdx stmt:(sqlite3_stmt*)stmt {
     int columnType = sqlite3_column_type(stmt, columnIdx);
 
@@ -184,7 +182,7 @@ - (id)objectForColumnIndex:(int)columnIdx stmt:(sqlite3_stmt*)stmt {
             return [self stringForColumnIndex:columnIdx stmt:stmt] ?: NSNull.null;
     }
 }
-
+                
 - (NSString *)stringForColumnIndex:(int)columnIdx stmt:(sqlite3_stmt *)stmt {
     if (sqlite3_column_type(stmt, columnIdx) == SQLITE_NULL || columnIdx < 0) {
         return nil;

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXTableContentViewController.h

@@ -10,7 +10,7 @@
 
 @interface FLEXTableContentViewController : UIViewController
 
-@property (nonatomic) NSArray<NSString *> *columns;
-@property (nonatomic) NSArray<NSArray *> *rows;
++ (instancetype)columns:(NSArray<NSString *> *)columnNames
+                   rows:(NSArray<NSArray<NSString *> *> *)rowData;
 
 @end

Classes/GlobalStateExplorers/DatabaseBrowser/FLEXTableContentViewController.m

@@ -14,21 +14,32 @@
 @interface FLEXTableContentViewController () <
     FLEXMultiColumnTableViewDataSource, FLEXMultiColumnTableViewDelegate
 >
+@property (nonatomic, readonly) NSArray<NSString *> *columns;
+@property (nonatomic, copy) NSArray<NSArray *> *rows;
+
 @property (nonatomic) FLEXMultiColumnTableView *multiColumnView;
 @end
 
 @implementation FLEXTableContentViewController
 
-- (void)viewDidLoad {
-    [super viewDidLoad];
-    self.edgesForExtendedLayout = UIRectEdgeNone;
-    
++ (instancetype)columns:(NSArray<NSString *> *)columnNames
+                   rows:(NSArray<NSArray<NSString *> *> *)rowData {
+    FLEXTableContentViewController *controller = [self new];
+    controller->_columns = columnNames;
+    controller->_rows = rowData;
+    return controller;
+}
+
+- (void)loadView {
+    [super loadView];
 
     [self.view addSubview:self.multiColumnView];
 }
 
-- (void)viewWillAppear:(BOOL)animated {
-    [super viewWillAppear:animated];
+- (void)viewDidLoad {
+    [super viewDidLoad];
+    
+    self.edgesForExtendedLayout = UIRectEdgeNone;
     [self.multiColumnView reloadData];
 }
 
@@ -38,8 +49,8 @@ - (FLEXMultiColumnTableView *)multiColumnView {
             initWithFrame:FLEXRectSetSize(CGRectZero, self.view.frame.size)
         ];
 
-        _multiColumnView.dataSource       = self;
-        _multiColumnView.delegate         = self;
+        _multiColumnView.dataSource = self;
+        _multiColumnView.delegate   = self;
     }
 
     return _multiColumnView;