[TABLE MODEL] Implement CREATE/SHOW/DROP Function and user-defined scalar function

example/udf/src/main/java/org/apache/iotdb/udf/ScalarFunctionExample.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.udf;
+
+import org.apache.iotdb.udf.api.customizer.config.ScalarFunctionConfig;
+import org.apache.iotdb.udf.api.customizer.parameter.FunctionParameters;
+import org.apache.iotdb.udf.api.exception.UDFParameterNotValidException;
+import org.apache.iotdb.udf.api.relational.ScalarFunction;
+import org.apache.iotdb.udf.api.relational.access.Record;
+import org.apache.iotdb.udf.api.type.Type;
+
+/** This is an internal example of the ScalarFunction implementation. */
+public class ScalarFunctionExample implements ScalarFunction {
+  /**
+   * CREATE DATABASE test;
+   *
+   * <p>USE test;
+   *
+   * <p>CREATE TABLE t1(device_id STRING ID, s1 TEXT MEASUREMENT, s2 INT32 MEASUREMENT);
+   *
+   * <p>INSERT INTO t1(time, device_id, s1, s2) VALUES (1, 'd1', 'a', 1), (2, 'd1', null, 2), (3,
+   * 'd1', 'c', null);
+   *
+   * <p>CREATE FUNCTION contain_null AS 'org.apache.iotdb.udf.ScalarFunctionExample';
+   *
+   * <p>SHOW FUNCTIONS;
+   *
+   * <p>SELECT time, device_id, s1, s2, contain_null(s1, s2) as contain_null, contain_null(s1) as
+   * s1_isnull, contain_null(s2) as s2_isnull FROM t1;
+   */
+  @Override
+  public void validate(FunctionParameters parameters) throws Exception {
+    if (parameters.getChildExpressionsSize() < 1) {
+      throw new UDFParameterNotValidException("At least one parameter is required.");
+    }
+  }
+
+  @Override
+  public void beforeStart(FunctionParameters parameters, ScalarFunctionConfig configurations) {
+    configurations.setOutputDataType(Type.BOOLEAN);
+  }
+
+  @Override
+  public Object evaluate(Record input) throws Exception {
+    for (int i = 0; i < input.size(); i++) {
+      if (input.isNull(i)) {
+        return true;
+      }
+    }
+    return false;
+  }
+}

integration-test/src/main/java/org/apache/iotdb/db/query/udf/example/relational/AllSum.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.db.query.udf.example.relational;
+
+import org.apache.iotdb.udf.api.customizer.config.ScalarFunctionConfig;
+import org.apache.iotdb.udf.api.customizer.parameter.FunctionParameters;
+import org.apache.iotdb.udf.api.exception.UDFParameterNotValidException;
+import org.apache.iotdb.udf.api.relational.ScalarFunction;
+import org.apache.iotdb.udf.api.relational.access.Record;
+import org.apache.iotdb.udf.api.type.Type;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/** Calculate the sum of all parameters. Only support inputs of INT32,INT64,DOUBLE,FLOAT type. */
+public class AllSum implements ScalarFunction {
+
+  private Type outputDataType;
+
+  @Override
+  public void validate(FunctionParameters parameters) throws Exception {
+    if (parameters.getChildExpressionsSize() < 1) {
+      throw new UDFParameterNotValidException("At least one parameter is required.");
+    }
+    for (int i = 0; i < parameters.getChildExpressionsSize(); i++) {
+      if (parameters.getDataType(i) != Type.INT32
+          && parameters.getDataType(i) != Type.INT64
+          && parameters.getDataType(i) != Type.FLOAT
+          && parameters.getDataType(i) != Type.DOUBLE) {
+        throw new UDFParameterNotValidException(
+            "Only support inputs of INT32,INT64,DOUBLE,FLOAT type.");
+      }
+    }
+  }
+
+  @Override
+  public void beforeStart(FunctionParameters parameters, ScalarFunctionConfig configurations) {
+    Set<Type> inputTypeSet = new HashSet<>();
+    for (int i = 0; i < parameters.getChildExpressionsSize(); i++) {
+      inputTypeSet.add(parameters.getDataType(i));
+    }
+    if (inputTypeSet.contains(Type.DOUBLE)) {
+      outputDataType = Type.DOUBLE;
+    } else if (inputTypeSet.contains(Type.FLOAT)) {
+      outputDataType = Type.FLOAT;
+    } else if (inputTypeSet.contains(Type.INT64)) {
+      outputDataType = Type.INT64;
+    } else {
+      outputDataType = Type.INT32;
+    }
+    configurations.setOutputDataType(outputDataType);
+  }
+
+  @Override
+  public Object evaluate(Record input) throws Exception {
+    double res = 0;
+    for (int i = 0; i < input.size(); i++) {
+      if (!input.isNull(i)) {
+        switch (input.getDataType(i)) {
+          case INT32:
+            res += input.getInt(i);
+            break;
+          case INT64:
+            res += input.getLong(i);
+            break;
+          case FLOAT:
+            res += input.getFloat(i);
+            break;
+          case DOUBLE:
+            res += input.getDouble(i);
+            break;
+        }
+      }
+    }
+    switch (outputDataType) {
+      case INT32:
+        return (int) res;
+      case INT64:
+        return (long) res;
+      case FLOAT:
+        return (float) res;
+      case DOUBLE:
+        return res;
+      default:
+        throw new RuntimeException("Unexpected output type.");
+    }
+  }
+}

integration-test/src/main/java/org/apache/iotdb/db/query/udf/example/relational/ContainNull.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.db.query.udf.example.relational;
+
+import org.apache.iotdb.udf.api.customizer.config.ScalarFunctionConfig;
+import org.apache.iotdb.udf.api.customizer.parameter.FunctionParameters;
+import org.apache.iotdb.udf.api.exception.UDFParameterNotValidException;
+import org.apache.iotdb.udf.api.relational.ScalarFunction;
+import org.apache.iotdb.udf.api.relational.access.Record;
+import org.apache.iotdb.udf.api.type.Type;
+
+public class ContainNull implements ScalarFunction {
+  @Override
+  public void validate(FunctionParameters parameters) throws Exception {
+    if (parameters.getChildExpressionsSize() < 1) {
+      throw new UDFParameterNotValidException("At least one parameter is required.");
+    }
+  }
+
+  @Override
+  public void beforeStart(FunctionParameters parameters, ScalarFunctionConfig configurations) {
+    configurations.setOutputDataType(Type.BOOLEAN);
+  }
+
+  @Override
+  public Object evaluate(Record input) throws Exception {
+    for (int i = 0; i < input.size(); i++) {
+      if (input.isNull(i)) {
+        return true;
+      }
+    }
+    return false;
+  }
+}