Save rating to database

1 files changed, 102 insertions, 0 deletions

diff --git a/src/database/QueryUtils.java b/src/database/QueryUtils.java
new file mode 100644
index 0000000..9aab081
--- /dev/null
+++ b/src/database/QueryUtils.java
@@ -0,0 +1,102 @@
+package database;
+
+import java.sql.SQLException;
+import java.util.Locale;
+
+/**
+ * Utilities to create queries.
+ *
+ * @author Maurice Laveaux
+ */
+public class QueryUtils {
+    public final static String insertRating 
+            = buildQuery("mentionsbrand", new String[]{"tweetid","brand"},"tweetid","brand", "rating");
+    public final static String insertProfile
+            = buildQuery("twitteruser", new String[]{"userid"},
+            "userid", "displayname", "timezone", "tweetcount", "followercount",
+            "followedcount", "location", "tweetname", "createdat::timestamptz",
+            "language", "description", "verified");
+
+    public final static String insertTweet
+            = buildQuery("tweet", new String[]{"tweetid"},
+            "tweetid", "createdat::timestamptz", "favcount", "retweetcount",
+            "text", "coordinates::point",
+            "language", "retweetid", "replyid", "place",
+            "userid");
+
+    public final static String insertHash
+            = buildQuery("hashtag", null, "tweetid", "hashtag");
+
+    public final static String insertUserUrl
+            = buildQuery("userUrl", null, "userid", "url");
+
+    public final static String insertTweetUrl
+            = buildQuery("tweetUrl", null, "tweetid", "url");
+
+    public final static String insertMentions
+            = buildQuery("mentionsuser", null, "tweetid", "userid");
+
+    public final static String insertBrand
+            = buildQuery("mentionsbrand", null, "tweetid", "brand");
+
+    /**
+     * Builds an upsert query for a table and keys.
+     *
+     * @param table Table to insert or update the data.
+     * @param primaryKeys The primary keys for the table or null if all keys
+     * form the primary key.
+     * @param keys The keys to be inserted or updated.
+     * @return A SQL query containing named parameters.
+     */
+    private static String buildQuery(String table, String[] primaryKeys,
+            String... keys) {
+        String sep = "";
+        String fields = ""; // a, b, c
+        String values = ""; // :a, :b, :c
+        String set_values = ""; // a = nv.a, b = nv.b, c = nv.c
+        String pkey_matches = "";
+        for (String field : keys) {
+            String key = field.replaceFirst("::\\w+", "");
+            fields += sep + key;
+            values += sep + ":" + field;
+            // "u" is "table that gets updated", "nv" is "new values"
+            set_values += sep + key + " = nv." + key;
+            sep = ", ";
+        }
+        sep = "";
+        // assume that all fields form the primary key if pks are missing
+        if (primaryKeys == null) {
+            primaryKeys = keys;
+        }
+        for (String pkey : primaryKeys) {
+            assert !pkey.contains("::") : "Specify primary keys when type cast is given";
+            pkey_matches += sep + "u." + pkey + " = nv." + pkey;
+            sep = " AND ";
+        }
+
+        String sql;
+        // CTE that holds new values
+        sql = "WITH nv (" + fields + ") AS (\n";
+        sql += "    VALUES (" + values + ")\n";
+        sql += ")\n";
+        // CTE that tries to update the table with new values (PSQL extension)
+        sql += ", upsert AS (\n";
+        sql += "    UPDATE " + table + " u SET " + set_values + " FROM nv\n";
+        sql += "    WHERE " + pkey_matches + " RETURNING 1\n";
+        sql += ")\n";
+        // if nothing got updated, insert new entry
+        sql += "INSERT INTO " + table + " (" + fields + ")\n";
+        sql += "SELECT " + fields + " FROM nv\n";
+        sql += "WHERE NOT EXISTS (SELECT 1 FROM upsert)";
+        return sql;
+    }
+
+    public static void setInsertParams(NamedPreparedStatement statement,
+            Long tweetid, String brand, int rating) throws SQLException {
+        statement.setLong("tweetid", tweetid);
+        statement.setInt("rating", rating);
+        statement.setString("brand", brand);
+        
+    }
+
+}