feat: support query builder

ci/checkstyle/suppressions.xml

@@ -14,4 +14,7 @@
 
     <!-- we don't need package-info on tests -->
     <suppress checks="JavadocPackage" files=".*[\\/]src[\\/]test[\\/].*"/>
+
+    <!-- Suppress LineLength rule for QueryBuilderTest.java -->
+    <suppress checks="LineLength" files=".*QueryBuilderTest\.java"/>
 </suppressions>

opengemini-client-api/src/main/java/io/opengemini/client/api/ArithmeticExpression.java

@@ -0,0 +1,35 @@
+package io.opengemini.client.api;
+
+/**
+ * ArithmeticExpression represents an arithmetic operation between two expressions
+ */
+public class ArithmeticExpression implements Expression {
+    private final Expression left;
+
+    private final Expression right;
+
+    private final ArithmeticOperator operator;
+
+    public ArithmeticExpression(Expression left, Expression right, ArithmeticOperator operator) {
+        this.left = left;
+        this.right = right;
+        this.operator = operator;
+    }
+
+    public Expression left() {
+        return left;
+    }
+
+    public Expression right() {
+        return right;
+    }
+
+    public ArithmeticOperator operator() {
+        return operator;
+    }
+
+    @Override
+    public String build() {
+        return "(" + left.build() + " " + operator.symbol() + " " + right.build() + ")";
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/ArithmeticOperator.java

@@ -0,0 +1,19 @@
+package io.opengemini.client.api;
+
+public enum ArithmeticOperator {
+    ADD("+"),
+    SUBTRACT("-"),
+    MULTIPLY("*"),
+    DIVIDE("/"),
+    MODULO("%");
+
+    private final String symbol;
+
+    ArithmeticOperator(String symbol) {
+        this.symbol = symbol;
+    }
+
+    public String symbol() {
+        return symbol;
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/AsExpression.java

@@ -0,0 +1,28 @@
+package io.opengemini.client.api;
+
+/**
+ * AsExpression represents an alias for an expression (e.g., SELECT field AS alias)
+ */
+public class AsExpression implements Expression {
+    private final String alias;
+
+    private final Expression expression;
+
+    public AsExpression(String alias, Expression expression) {
+        this.alias = alias;
+        this.expression = expression;
+    }
+
+    public String alias() {
+        return alias;
+    }
+
+    public Expression expression() {
+        return expression;
+    }
+
+    @Override
+    public String build() {
+        return expression.build() + " AS \"" + alias + "\"";
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/ComparisonCondition.java

@@ -0,0 +1,33 @@
+package io.opengemini.client.api;
+
+public class ComparisonCondition implements Condition {
+    private final String column;
+
+    private final ComparisonOperator operator;
+
+    private final Object value;
+
+    public ComparisonCondition(String column, ComparisonOperator operator, Object value) {
+        this.column = column;
+        this.operator = operator;
+        this.value = value;
+    }
+
+    @Override
+    public String build() {
+        StringBuilder conditionBuilder = new StringBuilder();
+        conditionBuilder.append('"');
+        conditionBuilder.append(column);
+        conditionBuilder.append('"');
+        conditionBuilder.append(" ");
+        conditionBuilder.append(operator.symbol());
+        conditionBuilder.append(" ");
+        if (value instanceof String) {
+            conditionBuilder.append("'").append(value).append("'");
+        } else {
+            conditionBuilder.append(value);
+        }
+
+        return conditionBuilder.toString();
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/ComparisonOperator.java

@@ -0,0 +1,20 @@
+package io.opengemini.client.api;
+
+public enum ComparisonOperator {
+    EQUALS("="),
+    NOT_EQUALS("<>"),
+    GREATER_THAN(">"),
+    LESS_THAN("<"),
+    GREATER_THAN_OR_EQUALS(">="),
+    LESS_THAN_OR_EQUALS("<=");
+
+    private final String symbol;
+
+    ComparisonOperator(String symbol) {
+        this.symbol = symbol;
+    }
+
+    public String symbol() {
+        return symbol;
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/CompositeCondition.java

@@ -0,0 +1,24 @@
+package io.opengemini.client.api;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class CompositeCondition implements Condition {
+    private final LogicalOperator logicalOperator;
+
+    private final Condition[] conditions;
+
+    public CompositeCondition(LogicalOperator logicalOperator, Condition... conditions) {
+        this.logicalOperator = logicalOperator;
+        this.conditions = conditions;
+    }
+
+    @Override
+    public String build() {
+        List<String> parts = new ArrayList<>();
+        for (Condition condition : conditions) {
+            parts.add(condition.build());
+        }
+        return "(" + String.join(" " + logicalOperator.name() + " ", parts) + ")";
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/Condition.java

@@ -0,0 +1,5 @@
+package io.opengemini.client.api;
+
+public interface Condition {
+    String build();
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/ConstantExpression.java

@@ -0,0 +1,21 @@
+package io.opengemini.client.api;
+
+/**
+ * ConstantExpression represents a constant value in the query
+ */
+public class ConstantExpression implements Expression {
+    private final Object value;
+
+    public ConstantExpression(Object value) {
+        this.value = value;
+    }
+
+    public Object value() {
+        return value;
+    }
+
+    @Override
+    public String build() {
+        return value.toString();
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/Expression.java

@@ -0,0 +1,5 @@
+package io.opengemini.client.api;
+
+public interface Expression {
+    String build();
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/FieldExpression.java

@@ -0,0 +1,21 @@
+package io.opengemini.client.api;
+
+/**
+ * FieldExpression represents a column or field in the query
+ */
+public class FieldExpression implements Expression {
+    private final String field;
+
+    public FieldExpression(String field) {
+        this.field = field;
+    }
+
+    public String field() {
+        return field;
+    }
+
+    @Override
+    public String build() {
+        return "\"" + field + "\"";
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/FunctionEnum.java

@@ -0,0 +1,12 @@
+package io.opengemini.client.api;
+
+public enum FunctionEnum {
+    MEAN,
+    COUNT,
+    SUM,
+    MIN,
+    MAX,
+    TIME,
+    TOP,
+    LAST,
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/FunctionExpression.java

@@ -0,0 +1,39 @@
+package io.opengemini.client.api;
+
+/**
+ * FunctionExpression represents a function call with arguments (e.g., SUM, COUNT)
+ */
+public class FunctionExpression implements Expression {
+    private final FunctionEnum function;
+
+    private final Expression[] arguments;
+
+    public FunctionExpression(FunctionEnum function, Expression[] arguments) {
+        this.function = function;
+        this.arguments = arguments;
+    }
+
+    public FunctionEnum function() {
+        return function;
+    }
+
+    public Expression[] arguments() {
+        return arguments;
+    }
+
+    @Override
+    public String build() {
+        StringBuilder builder = new StringBuilder();
+        builder.append(function.name()).append("(");
+
+        for (int i = 0; i < arguments.length; i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            builder.append(arguments[i].build());
+        }
+
+        builder.append(")");
+        return builder.toString();
+    }
+}

opengemini-client-api/src/main/java/io/opengemini/client/api/LogicalOperator.java

@@ -0,0 +1,6 @@
+package io.opengemini.client.api;
+
+public enum LogicalOperator {
+    AND,
+    OR,
+}