Oracle Faker

OracleFakerInsert.java

import java.sql.*;
import java.time.LocalDateTime;
import java.util.*;

import com.github.javafaker.Faker;


public class OracleTableFaker {
    public static void main(String[] args) throws Exception {
        Faker faker = new Faker();

        // --- SET THESE ---
        String url = "jdbc:oracle:thin:@//HOST:PORT/SERVICE";  // e.g., @//localhost:1521/XEPDB1
        String user = "your_username";
        String password = "your_password";
        String tableName = "USERS";

        // --- Connect ---
        Class.forName("oracle.jdbc.driver.OracleDriver");
        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            DatabaseMetaData meta = conn.getMetaData();

            // --- Get column metadata ---
            ResultSet rs = meta.getColumns(null, user.toUpperCase(), tableName.toUpperCase(), null);
            List<ColumnInfo> columns = new ArrayList<>();

            while (rs.next()) {
                String columnName = rs.getString("COLUMN_NAME");
                String typeName = rs.getString("TYPE_NAME");
                int dataType = rs.getInt("DATA_TYPE");

                columns.add(new ColumnInfo(columnName, typeName, dataType));
            }

            if (columns.isEmpty()) {
                System.out.println("No columns found or table doesn't exist.");
                return;
            }

            // --- Generate and print INSERT statements ---
            for (int i = 0; i < 5; i++) {  // insert 5 fake rows
                StringBuilder insert = new StringBuilder("INSERT INTO " + tableName + " (");
                StringBuilder values = new StringBuilder("VALUES (");

                for (int j = 0; j < columns.size(); j++) {
                    ColumnInfo col = columns.get(j);
                    insert.append(col.name);
                    values.append(fakeValueFor(col, faker));

                    if (j < columns.size() - 1) {
                        insert.append(", ");
                        values.append(", ");
                    }
                }

                insert.append(") ");
                values.append(");");

                String fullInsert = insert.toString() + values.toString();
                System.out.println(fullInsert);
            }
        }
    }

    // --- ColumnInfo class to hold metadata ---
    static class ColumnInfo {
        String name;
        String typeName;
        int sqlType;

        ColumnInfo(String name, String typeName, int sqlType) {
            this.name = name;
            this.typeName = typeName;
            this.sqlType = sqlType;
        }
    }

    // --- Generate fake value based on SQL type ---
    static String fakeValueFor(ColumnInfo col, Faker faker) {
        switch (col.sqlType) {
            case Types.VARCHAR:
            case Types.CHAR:
                return "'" + faker.lorem().characters(8) + "'";
            case Types.INTEGER:
            case Types.NUMERIC:
            case Types.DECIMAL:
            case Types.BIGINT:
            case Types.SMALLINT:
                return String.valueOf(faker.number().numberBetween(1, 9999));
            case Types.TIMESTAMP:
            case Types.DATE:
                return "TO_DATE('" + java.sql.Date.valueOf(LocalDateTime.now().toLocalDate()) + "', 'YYYY-MM-DD')";
            case Types.FLOAT:
            case Types.DOUBLE:
                return String.valueOf(faker.number().randomDouble(2, 1, 100));
            default:
                return "NULL";  // fallback for unsupported types
        }
    }
}