protobuf4j.orm.sql.SqlUtil Maven / Gradle / Ivy

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package protobuf4j.orm.sql;

import com.google.common.base.CaseFormat;
import org.apache.commons.lang3.StringUtils;
import protobuf4j.orm.sql.clause.SelectItem;
import protobuf4j.orm.sql.expr.AbstractExpression;
import protobuf4j.orm.sql.expr.RawExpr;

import javax.annotation.Nonnull;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

/**
 * author: yuanwq
 * date: 2018/7/15
 */
public abstract class SqlUtil {
  public static String defaultTableName(Class cls) {
    return CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, cls.getSimpleName());
  }

  public static final SelectItem SELECT_STAR = new SelectItem(new RawExpr("*")) {
    @Override
    public void setAlias(String alias) {
      throw new UnsupportedOperationException("cannot set alias for STAR `*`");
    }
  };
  public static final SelectItem SELECT_COUNT = new SelectItem(new RawExpr("COUNT(1)")) {
    @Override
    public void setAlias(String alias) {
      throw new UnsupportedOperationException("cannot set alias for DEFAULT `COUNT(1)`");
    }
  };

  private SqlUtil() {
  }

  public static IExpression aggregateWrap(String aggregateFunc, IExpression expr) {
    return new AbstractExpression() {
      @Override
      public int comparePrecedence(@Nonnull ISqlOperator outerOp) {
        return 1;
      }

      @Override
      public StringBuilder toSqlTemplate(@Nonnull StringBuilder sb) {
        sb.append(aggregateFunc).append("(");
        expr.toSqlTemplate(sb);
        sb.append(")");
        return sb;
      }

      @Override
      public StringBuilder toSolidSql(@Nonnull StringBuilder sb) {
        sb.append(aggregateFunc).append("(");
        expr.toSolidSql(sb);
        sb.append(")");
        return sb;
      }

      @Override
      public List collectSqlValue(@Nonnull List sqlValues) {
        expr.collectSqlValue(sqlValues);
        return sqlValues;
      }
    };
  }

  /**
   * 将{@code sqlTemplate}中的{@code "?"}按顺序使用{@code values}中的值进行替换，若values不足，则保留{@code "?"}
   */
  public static String replaceParamHolder(String sqlTemplate, Collection values) {
    StringBuilder sb = new StringBuilder();
    Iterator iter = values.iterator();
    boolean first = true;
    for (String part : StringUtils.splitPreserveAllTokens(sqlTemplate, "?")) {
      if (first) {
        first = false;
      } else {
        if (iter.hasNext()) {
          sb.append(iter.next());
        } else {
          sb.append("?");
        }
      }
      sb.append(part);
    }
    return sb.toString();
  }

  private static String escapePercent(String word) {
    return word.replace("%", "%%");
  }

  /**
   * LIKE 'xxx%'
   */
  public static String likePrefix(String prefix) {
    return escapePercent(prefix) + "%";
  }

  /**
   * LIKE '%xxx'
   */
  public static String likeSuffix(String suffix) {
    return "%" + escapePercent(suffix);
  }

  /**
   * LIKE '%xxx%'
   */
  public static String likeSub(String substring) {
    return "%" + escapePercent(substring) + "%";
  }

}