org.hotrod.runtime.livesql.dialects.H2Dialect Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of hotrod-livesql Show documentation
HotRod is an ORM for Java, Spring and SpringBoot.
There is a newer version: 4.8.1
package org.hotrod.runtime.livesql.dialects;

import org.hotrod.runtime.livesql.exceptions.InvalidLiveSQLStatementException;
import org.hotrod.runtime.livesql.exceptions.UnsupportedLiveSQLFeatureException;
import org.hotrod.runtime.livesql.expressions.datetime.DateTimeExpression;
import org.hotrod.runtime.livesql.expressions.numbers.NumberExpression;
import org.hotrod.runtime.livesql.queries.select.CrossJoin;
import org.hotrod.runtime.livesql.queries.select.FullOuterJoin;
import org.hotrod.runtime.livesql.queries.select.InnerJoin;
import org.hotrod.runtime.livesql.queries.select.Join;
import org.hotrod.runtime.livesql.queries.select.LeftOuterJoin;
import org.hotrod.runtime.livesql.queries.select.NaturalFullOuterJoin;
import org.hotrod.runtime.livesql.queries.select.NaturalInnerJoin;
import org.hotrod.runtime.livesql.queries.select.NaturalLeftOuterJoin;
import org.hotrod.runtime.livesql.queries.select.NaturalRightOuterJoin;
import org.hotrod.runtime.livesql.queries.select.QueryWriter;
import org.hotrod.runtime.livesql.queries.select.RightOuterJoin;
import org.hotrod.runtime.livesql.queries.select.UnionJoin;

public class H2Dialect extends SQLDialect {

  public H2Dialect(final String productName, final String productVersion, final int majorVersion,
      final int minorVersion) {
    super(productName, productVersion, majorVersion, minorVersion);
  }

  // Identifier rendering

  @Override
  public IdentifierRenderer getIdentifierRenderer() {
    // Identifier names are by default upper case in H2
    return new IdentifierRenderer("[A-Z][A-Z0-9_]*", "\"", "\"", false);
  }

  // Join rendering

  @Override
  public JoinRenderer getJoinRenderer() {
    return new JoinRenderer() {

      @Override
      public String renderJoinKeywords(final Join join) throws UnsupportedLiveSQLFeatureException {
        if (join instanceof InnerJoin) {
          return "JOIN";
        } else if (join instanceof LeftOuterJoin) {
          return "LEFT OUTER JOIN";
        } else if (join instanceof RightOuterJoin) {
          return "RIGHT OUTER JOIN";
        } else if (join instanceof FullOuterJoin) {
          return "FULL OUTER JOIN";
        } else if (join instanceof CrossJoin) {
          return "CROSS JOIN";
        } else if (join instanceof NaturalInnerJoin) {
          return "NATURAL JOIN";
        } else if (join instanceof NaturalLeftOuterJoin) {
          return "NATURAL LEFT OUTER JOIN";
        } else if (join instanceof NaturalRightOuterJoin) {
          return "NATURAL RIGHT OUTER JOIN";
        } else if (join instanceof NaturalFullOuterJoin) {
          return "NATURAL FULL OUTER JOIN";
        } else if (join instanceof UnionJoin) {
          throw new UnsupportedLiveSQLFeatureException("Union joins are not supported in H2 database");
        } else {
          throw new UnsupportedLiveSQLFeatureException(
              "Invalid join type (" + join.getClass().getSimpleName() + ") in H2 database");
        }
      }

    };
  }

  // Pagination rendering

  public PaginationRenderer getPaginationRenderer() {
    return new PaginationRenderer() {

      @Override
      public PaginationType getPaginationType(final Integer offset, final Integer limit) {
        return offset != null || limit != null ? PaginationType.BOTTOM : null;
      }

      @Override
      public void renderTopPagination(final Integer offset, final Integer limit, final QueryWriter w) {
        throw new UnsupportedLiveSQLFeatureException("Pagination can only be rendered at the bottom in H2");
      }

      @Override
      public void renderBottomPagination(final Integer offset, final Integer limit, final QueryWriter w) {
        if (limit != null) {
          if (offset != null) {
            w.write("\nLIMIT " + limit + " OFFSET " + offset);
          } else {
            w.write("\nLIMIT " + limit);
          }
        } else {
          w.write("\nOFFSET " + offset);
        }
      }

      @Override
      public void renderBeginEnclosingPagination(final Integer offset, final Integer limit, final QueryWriter w) {
        throw new UnsupportedLiveSQLFeatureException("Pagination can only be rendered at the bottom in H2");
      }

      @Override
      public void renderEndEnclosingPagination(final Integer offset, final Integer limit, final QueryWriter w) {
        throw new UnsupportedLiveSQLFeatureException("Pagination can only be rendered at the bottom in H2");
      }

    };
  }

  // Set operation rendering

  @Override
  public SetOperationRenderer getSetOperationRenderer() {
    return new SetOperationRenderer() {

      @Override
      public void render(final SetOperation setOperation, final QueryWriter w) {
        switch (setOperation) {
        case UNION:
          w.write("UNION");
          break;
        case UNION_ALL:
          w.write("UNION ALL");
          break;
        case INTERSECT:
          w.write("INTERSECT");
          break;
        case INTERSECT_ALL:
          throw new UnsupportedLiveSQLFeatureException("H2 database does not support the INTERSECT ALL set operation. "
              + "Nevertheless, it can be simulated using a semi join");
        case EXCEPT:
          w.write("EXCEPT");
          break;
        case EXCEPT_ALL:
          throw new UnsupportedLiveSQLFeatureException("H2 database does not support the EXCEPT ALL set operation. "
              + "Nevertheless, it can be simulated using an anti join");
        default:
          throw new InvalidLiveSQLStatementException("Invalid set operation '" + setOperation + "'.");
        }
      }

    };
  }

  // Function rendering

  @Override
  public FunctionRenderer getFunctionRenderer() {
    return new FunctionRenderer() {

      // General purpose functions

      // Arithmetic functions

      @Override
      public void logarithm(final QueryWriter w, final NumberExpression x, final NumberExpression base) {
        if (base == null) {
          this.write(w, "ln", x);
        } else {
          w.write("(");
          this.write(w, "ln", x);
          w.write(" / ");
          this.write(w, "ln", base);
          w.write(")");
        }
      }

      public void trunc(final QueryWriter w, final NumberExpression x, final NumberExpression places) {
        if (places == null) {
          throw new UnsupportedLiveSQLFeatureException(
              "H2 requires the number of decimal places to be specified when using the TRUNC() function");
        }
        this.write(w, "trunc", x, places);
      }

      // String functions

      // Date/Time functions

      @Override
      public void date(final QueryWriter w, final DateTimeExpression datetime) {
        w.write("cast(");
        datetime.renderTo(w);
        w.write(" as date)");
      }

      @Override
      public void time(final QueryWriter w, final DateTimeExpression datetime) {
        w.write("cast(");
        datetime.renderTo(w);
        w.write(" as time)");
      }

      @Override
      public void dateTime(final QueryWriter w, final DateTimeExpression date, final DateTimeExpression time) {
        w.write("(");
        date.renderTo(w);
        w.write(" + ");
        time.renderTo(w);
        w.write(")");
      }

    };
  }

}