added crud

app/src/main/java/com/wyattjmiller/classscheduleapp/CourseDatabase.kt

@@ -0,0 +1,147 @@
+package com.wyattjmiller.classscheduleapp
+
+import android.content.ContentValues
+import android.content.Context
+import android.database.sqlite.SQLiteDatabase
+import android.database.sqlite.SQLiteOpenHelper
+import android.os.Build
+import java.util.ArrayList
+
+class CourseDatabase private constructor(context: Context) : SQLiteOpenHelper(context, DATABASE_NAME, null, VERSION) {
+    override fun onCreate(db: SQLiteDatabase) {
+        db.execSQL(
+            "create table " + CourseTable.TABLE + " (" +
+                    CourseTable.COL_ID + " primary key autoincrement, " +
+                    CourseTable.COL_NAME + " int, " +
+                    CourseTable.COL_DESCRIPTION + " string, " +
+                    CourseTable.COL_LOCATION + " string, " +
+                    CourseTable.COL_DAYOFWEEK + " string, " +
+                    CourseTable.COL_TIME + " string, " +
+                    CourseTable.COL_INSTRUCTOR + " string, " +
+                    CourseTable.COL_UPDATE_TIME + " int)"
+        )
+
+        val course = Course()
+        val values = ContentValues()
+        values.put(CourseTable.COL_NAME, course.name)
+        db.insert(CourseTable.TABLE, null, values)
+
+    }
+
+    override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
+        db.execSQL("drop table if exists " + CourseTable.TABLE)
+        onCreate(db)
+    }
+
+    override fun onOpen(db: SQLiteDatabase) {
+        super.onOpen(db)
+
+        if (!db.isReadOnly) {
+            // Enable foreign key constraints
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
+                db.execSQL("pragma foreign_keys = on;")
+            } else {
+                db.setForeignKeyConstraintsEnabled(true)
+            }
+        }
+    }
+
+    fun getCourses(course: String): List<Course> {
+        val courses: MutableList<Course> = ArrayList<Course>()
+        val db = this.readableDatabase
+        val sql = ("select * from " + CourseTable.TABLE)
+        val cursor = db.rawQuery(sql, arrayOf(course))
+
+        if (cursor.moveToFirst()) {
+            do {
+                val course = Course()
+                course.id = cursor.getLong(0)
+                course.name = cursor.getString(1)
+                course.description = cursor.getString(2)
+                course.location = cursor.getString(3)
+                course.dayOfWeek = cursor.getString(4)
+                course.time = cursor.getString(5)
+                course.instructor = cursor.getString(6)
+                courses.add(course)
+            } while (cursor.moveToNext())
+        }
+
+        cursor.close()
+        return courses
+    }
+
+    fun getCourse(questionId: Long): Course? {
+        var course: Course? = null
+        val db = this.readableDatabase
+        val sql = ("select * from " + CourseTable.TABLE +
+                " where " + CourseTable.COL_ID + " = ?")
+        val cursor = db.rawQuery(sql, arrayOf(java.lang.Float.toString(questionId.toFloat())))
+
+        if (cursor.moveToFirst()) {
+            course?.id = cursor.getLong(0)
+            course?.name = cursor.getString(1)
+            course?.description = cursor.getString(2)
+            course?.location = cursor.getString(3)
+            course?.dayOfWeek = cursor.getString(4)
+            course?.time = cursor.getString(5)
+            course?.instructor = cursor.getString(6)
+        }
+
+        return course
+    }
+
+    fun addCourse(course: Course) {
+        val db = writableDatabase
+        val values = ContentValues()
+
+        values.put(CourseTable.COL_NAME, course.name)
+        values.put(CourseTable.COL_DESCRIPTION, course.description)
+        values.put(CourseTable.COL_LOCATION, course.location)
+        values.put(CourseTable.COL_DAYOFWEEK, course.dayOfWeek)
+        values.put(CourseTable.COL_TIME, course.time)
+        values.put(CourseTable.COL_INSTRUCTOR, course.instructor)
+
+        val courseId = db.insert(CourseTable.TABLE, null, values)
+
+        course.id = courseId
+    }
+
+    fun updateCourse(course: Course) {
+        val db = writableDatabase
+        val values = ContentValues()
+
+        values.put(CourseTable.COL_ID, course.id)
+        values.put(CourseTable.COL_NAME, course.name)
+        values.put(CourseTable.COL_DESCRIPTION, course.description)
+        values.put(CourseTable.COL_LOCATION, course.location)
+        values.put(CourseTable.COL_DAYOFWEEK, course.dayOfWeek)
+        values.put(CourseTable.COL_TIME, course.time)
+        values.put(CourseTable.COL_INSTRUCTOR, course.instructor)
+
+        db.update(
+            CourseTable.TABLE, values,
+            CourseTable.COL_ID + " = " + course.id, null
+        )
+    }
+
+    fun deleteCourse(courseId: Long) {
+        val db = writableDatabase
+        db.delete(
+            CourseTable.TABLE,
+            CourseTable.COL_ID + " = " + courseId, null
+        )
+    }
+
+    companion object {
+        private val VERSION = 1
+        private val DATABASE_NAME = "study.db"
+        private var mStudyDb: CourseDatabase? = null
+
+        fun getInstance(context: Context): CourseDatabase? {
+            if (mStudyDb == null) {
+                mStudyDb = CourseDatabase(context)
+            }
+            return mStudyDb
+        }
+    }
+}