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‎docs/SqlParamBuilder.md

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@@ -2,4 +2,89 @@
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Script template for working with relational database using JDBC.
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## The sample of usage
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If you want to run the Java class as a script, you need to download and connect the JDBC driver.
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You can use a Bash script `SqlExecutor.sh` that downloads the JDBC driver for the H2 database for for demonstration purposes.
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```java
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void mainStart(Connection dbConnection) throws Exception {
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try (SqlParamBuilder builder = new SqlParamBuilder(dbConnection)) {
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System.out.println("# CREATE TABLE");
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builder.sql("""
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CREATE TABLE employee
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( id INTEGER PRIMARY KEY
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, name VARCHAR(256) DEFAULT 'test'
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, code VARCHAR(1)
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, created DATE NOT NULL )
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""")
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.execute();
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System.out.println("# SINGLE INSERT");
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builder.sql("""
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INSERT INTO employee
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( id, code, created ) VALUES
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( :id, :code, :created )
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""")
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.bind("id", 1)
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.bind("code", "T")
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.bind("created", someDate)
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.execute();
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System.out.println("# MULTI INSERT");
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builder.sql("""
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INSERT INTO employee
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(id,code,created) VALUES
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(:id1,:code,:created),
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(:id2,:code,:created)
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""")
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.bind("id1", 2)
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.bind("id2", 3)
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.bind("code", "T")
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.bind("created", someDate.plusDays(7))
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.execute();
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builder.bind("id1", 11)
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.bind("id2", 12)
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.bind("code", "V")
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.execute();
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System.out.println("# SELECT");
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List<Employee> employees = builder.sql("""
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SELECT t.id, t.name, t.created
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FROM employee t
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WHERE t.id < :id
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AND t.code IN (:code)
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ORDER BY t.id
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""")
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.bind("id", 10)
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.bind("code", "T", "V")
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.streamMap(rs -> new Employee(
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rs.getInt("id"),
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rs.getString("name"),
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rs.getObject("created", LocalDate.class)))
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.toList();
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System.out.printf("# PRINT RESULT OF: %s%n", builder.toStringLine());
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employees.stream().forEach(System.out::println);
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assertEquals(3, employees.size());
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assertEquals(1, employees.get(0).id);
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assertEquals("test", employees.get(0).name);
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assertEquals(someDate, employees.get(0).created);
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assertEquals( """
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SELECT t.id, t.name, t.created
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FROM employee t
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WHERE t.id < [10]
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AND t.code IN ([T],[V])
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ORDER BY t.id
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""", builder.toString());
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}
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}
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record Employee (int id, String name, LocalDate created) {}
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static class SqlParamBuilder {…}
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```
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The result of only one `SqlParamBuilder` object can be processed at a time.
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For multiple simultaneous processing, multiple objects of the `SqlParamBuilder` type must be opened.
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For more information see a source code: [SqlExecutor.java](../src/main/java/net/ponec/script/SqlExecutor.java) .

‎pom.xml

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@@ -17,19 +17,12 @@
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</properties>
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<dependencies>
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<dependency>
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<groupId>org.junit.jupiter</groupId>
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<artifactId>junit-jupiter-engine</artifactId>
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<version>5.10.2</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>com.h2database</groupId>
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<artifactId>h2</artifactId>
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<version>2.2.224</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.jetbrains.kotlin</groupId>
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<artifactId>kotlin-stdlib-jdk8</artifactId>
@@ -41,6 +34,13 @@
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<version>${kotlin.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.junit.jupiter</groupId>
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<artifactId>junit-jupiter-engine</artifactId>
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<version>5.10.2</version>
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<scope>test</scope>
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</dependency>
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</dependencies>
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<build>

‎src/main/java/net/ponec/script/SqlExecutor.java

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@@ -38,8 +38,8 @@ void mainStart(Connection dbConnection) throws Exception {
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( id INTEGER PRIMARY KEY
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, name VARCHAR(256) DEFAULT 'test'
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, code VARCHAR(1)
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, created DATE NOT NULL
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)""")
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, created DATE NOT NULL )
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""")
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.execute();
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System.out.println("# SINGLE INSERT");
@@ -81,26 +81,24 @@ AND t.code IN (:code)
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.bind("id", 10)
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.bind("code", "T", "V")
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.streamMap(rs -> new Employee(
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rs.getInt(1),
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rs.getString(2),
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rs.getObject(3, LocalDate.class)))
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rs.getInt("id"),
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rs.getString("name"),
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rs.getObject("created", LocalDate.class)))
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.toList();
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System.out.printf("# PRINT RESULT OF: %s%n", builder.toStringLine());
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employees.stream().forEach(System.out::println);
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assertEquals(3, employees.size());
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assertEquals(1, employees.get(0).id);
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assertEquals("test", employees.get(0).name);
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assertEquals(someDate, employees.get(0).created);
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System.out.println("# REUSE THE SELECT\n");
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List<Employee> employees2 = builder
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.bind("id", 100)
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.streamMap(rs -> new Employee(
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rs.getInt(1),
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rs.getString(2),
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rs.getObject(3, LocalDate.class)))
101-
.toList();
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assertEquals(5, employees2.size());
103-
employees2.stream().forEach(System.out::println);
95+
assertEquals( """
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SELECT t.id, t.name, t.created
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FROM employee t
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WHERE t.id < [10]
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AND t.code IN ([T],[V])
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ORDER BY t.id
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""", builder.toString());
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}
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}
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@@ -132,16 +130,16 @@ private <T> void assertEquals(T expected, T result) {
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/**
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* Less than 170 lines long class to simplify work with JDBC.
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* Original source: <a href="https://github.com/pponec/DirectoryBookmarks/blob/development/utils/SqlExecutor.java">GitHub</a>
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* Original source: <a href="https://github.com/pponec/DirectoryBookmarks/blob/development/src/main/java/net/ponec/script/SqlExecutor.java">GitHub</a>
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* Licence: Apache License, Version 2.0
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* @author Pavel Ponec, https://github.com/pponec
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* @version 1.0.6
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* @version 1.0.7
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*/
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static class SqlParamBuilder implements Closeable {
141139
/** SQL parameter mark type of {@code :param} */
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private static final Pattern SQL_MARK = Pattern.compile(":(\\w+)");
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private final Connection dbConnection;
144-
private final Map<String, Object> params = new HashMap<>();
142+
private final Map<String, Object[]> params = new HashMap<>();
145143
private String sqlTemplate = null;
146144
private PreparedStatement preparedStatement = null;
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@@ -152,14 +150,13 @@ public SqlParamBuilder(Connection dbConnection) {
152150
/** Close statement (if any) and set a new SQL template */
153151
public SqlParamBuilder sql(String... sqlLines) {
154152
close();
155-
this.params.clear();
156-
this.sqlTemplate = sqlLines.length == 1 ? sqlLines[0] : String.join("\n", sqlLines);
153+
sqlTemplate = sqlLines.length == 1 ? sqlLines[0] : String.join("\n", sqlLines);
157154
return this;
158155
}
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160-
/** Assign a SQL value(s) */
161-
public SqlParamBuilder bind(String key, Object... value) {
162-
this.params.put(key, value.length == 1 ? value[0] : List.of(value));
157+
/** Assign a SQL value(s). In case a reused statement set the same number of parameters items. */
158+
public SqlParamBuilder bind(String key, Object... values) {
159+
params.put(key, values.length > 0 ? values : new Object[]{null});
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return this;
164161
}
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throw new IllegalStateException("Closing fails", e);
219216
} finally {
220217
preparedStatement = null;
218+
params.clear();
221219
}
222220
}
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224222
public PreparedStatement prepareStatement() throws SQLException {
225-
final var sqlValues = new ArrayList<>(params.size());
223+
final var sqlValues = new ArrayList<>();
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final var sql = buildSql(sqlValues, false);
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final var result = preparedStatement != null
228226
? preparedStatement
229227
: dbConnection.prepareStatement(sql);
230228
for (int i = 0, max = sqlValues.size(); i < max; i++) {
231229
result.setObject(i + 1, sqlValues.get(i));
232230
}
233-
this.preparedStatement = result;
231+
preparedStatement = result;
234232
return result;
235233
}
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237235
private String buildSql(List<Object> sqlValues, boolean toLog) {
238236
final var result = new StringBuilder(256);
239237
final var matcher = SQL_MARK.matcher(sqlTemplate);
240238
final var missingKeys = new HashSet<>();
241-
final var singleValue = new Object[1];
242239
while (matcher.find()) {
243240
final var key = matcher.group(1);
244-
final var value = params.get(key);
245-
if (value != null) {
241+
final var values = params.get(key);
242+
if (values != null) {
246243
matcher.appendReplacement(result, "");
247-
singleValue[0] = value;
248-
final Object[] values = value instanceof List ? ((List<?>) value).toArray() : singleValue;
249244
for (int i = 0; i < values.length; i++) {
250245
if (i > 0) result.append(',');
251246
result.append(Matcher.quoteReplacement(toLog ? "[" + values[i] + "]" : "?"));
@@ -272,6 +267,10 @@ public String toString() {
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return buildSql(new ArrayList<>(), true);
273268
}
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270+
public String toStringLine() {
271+
return toString().replaceAll("\\s*\\R+\\s*", " ");
272+
}
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@FunctionalInterface
276275
public interface SqlFunction<T, R> extends Function<T, R> {
277276
default R apply(T resultSet) {

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