rename PostgresQueryBuilder to PostgresMetaQuery

public/app/plugins/datasource/postgres/meta_query.ts

@@ -0,0 +1,74 @@
+export class PostgresMetaQuery {
+  constructor(private target, private queryModel) {}
+
+  // quote identifier as literal to use in metadata queries
+  quoteIdentAsLiteral(value) {
+    return this.queryModel.quoteLiteral(this.queryModel.unquoteIdentifier(value));
+  }
+
+  buildSchemaQuery() {
+    let query = 'SELECT quote_ident(schema_name) FROM information_schema.schemata WHERE';
+    query += " schema_name NOT LIKE 'pg_%' AND schema_name NOT LIKE '\\_%' AND schema_name <> 'information_schema';";
+
+    return query;
+  }
+
+  buildTableQuery() {
+    let query = 'SELECT quote_ident(table_name) FROM information_schema.tables WHERE ';
+    query += 'table_schema = ' + this.quoteIdentAsLiteral(this.target.schema);
+    return query;
+  }
+
+  buildColumnQuery(type?: string) {
+    let query = 'SELECT quote_ident(column_name) FROM information_schema.columns WHERE ';
+    query += 'table_schema = ' + this.quoteIdentAsLiteral(this.target.schema);
+    query += ' AND table_name = ' + this.quoteIdentAsLiteral(this.target.table);
+
+    switch (type) {
+      case 'time': {
+        query +=
+          " AND data_type IN ('timestamp without time zone','timestamp with time zone','bigint','integer','double precision','real')";
+        break;
+      }
+      case 'metric': {
+        query += " AND data_type IN ('text','char','varchar')";
+        break;
+      }
+      case 'value': {
+        query += " AND data_type IN ('bigint','integer','double precision','real')";
+        query += ' AND column_name <> ' + this.quoteIdentAsLiteral(this.target.timeColumn);
+        break;
+      }
+      case 'groupby': {
+        query += " AND data_type IN ('text','char','varchar')";
+        break;
+      }
+    }
+
+    return query;
+  }
+
+  buildValueQuery(column: string) {
+    let query = 'SELECT DISTINCT quote_literal(' + column + ')';
+    query += ' FROM ' + this.target.schema + '.' + this.target.table;
+    query += ' WHERE $__timeFilter(' + this.target.timeColumn + ')';
+    query += ' ORDER BY 1 LIMIT 100';
+    return query;
+  }
+
+  buildDatatypeQuery(column: string) {
+    let query = 'SELECT data_type FROM information_schema.columns WHERE ';
+    query += ' table_schema = ' + this.quoteIdentAsLiteral(this.target.schema);
+    query += ' AND table_name = ' + this.quoteIdentAsLiteral(this.target.table);
+    query += ' AND column_name = ' + this.quoteIdentAsLiteral(column);
+    return query;
+  }
+
+  buildAggregateQuery() {
+    let query = 'SELECT DISTINCT proname FROM pg_aggregate ';
+    query += 'INNER JOIN pg_proc ON pg_aggregate.aggfnoid = pg_proc.oid ';
+    query += 'INNER JOIN pg_type ON pg_type.oid=pg_proc.prorettype ';
+    query += "WHERE pronargs=1 AND typname IN ('float8') AND aggkind='n' ORDER BY 1";
+    return query;
+  }
+}